So, with all the hubbub about too much stealth or 0% missions, I figured I'd return to some Vanilla XCOM 2 while I waited for the future patches to shape the mod up. I decided to play it mechanically vanilla (except for the Free Reload Anytime mod and Retroactive AWC, which I've always used), to keep things as pure as possible.
My intention here is to look at what each version of the game could learn from the other one. This is not about the uniquely Long War mechanics of Infiltration, the viability of pure stealthing missions, or of the liberation chains. It's about what either game could take from the other, without changing the feel of it. Also, some of the things I'd like to see change are probably already covered by mods. No need to tell me about them. This is just for comparisons sake after having played it both ways.
So, first off, classes. Going back, I thought I was really going to miss the Long War classes. Twice as many base classes, with 3 times as many skill choices? How could I go back to a mere 8 skill trees after having 24? Well, playing Vanilla-ey, I found I was actually quite happy with what I had. Excepting a few dead perks (Aim? Really?), I found the base classes did a lot with what they had. While there isn't quite the same bevy of options, I rarely felt I was truly missing something from Long War. Sure, the Long War classes were a lot more powerful, so I was missing something in that sense. But then the enemies in Long War are a lot more powerful too.
A couple of notable exceptions. First off, I felt that the Specialist was a fairly strong contributor in Vanilla. While they've lost free Haywire Protocol, the Vanilla Assault Rifle is closer in power to the specialty weapons, and with no SMGs to carry around, I found that Specialists were nearly as good at gun-combat as the other classes. However, I don't think this is something that Long War needs to adopt, as it intentionally has tried to make more specialized classes. So it's acceptable to have Long War classes that aren't good at shooting in a way that it's not for Vanilla.
Still, I do miss my Scout Shinobis. A Phantom Ranger in Vanilla is no more stealthy than a regular soldier, which leads to the often-times bizarre behavior where I'll scout with anyone OTHER than my Ranger, so that when one person is revealed, it's not them, and they can continue to scout. While not in need of the several stealth specialized talents of the Shinobi, perhaps Phantom could include an additional passive effect equivalent to Long War Covert.
On the other hand, I was delighted to see the return of Gunslingers (until the Archon King killed her... *grumble*). While still trainable in the AWC, that takes time, and with the general increase of power of classes (and decrease in power of BS Rounds), the Gunslinger just isn't what it used to be, relatively speaking. Sure, they can get all the Gunslinger Talents, and also their class talents, but that's a lot of investment for a side-arm. There's no real Long War equivalent for the kind of high volume, low damage they can put out. Rangers are close, but without Showdown or Lightning Hands, we're still only talking two targets per round.
On the subject of the AWC, I kind of feel the Vanilla AWC could use a small update. While getting 6 abilities is part of the higher-power level of LW, the very random nature of the abilities could stand to be a little more controlled. I'd gladly have a little bit of required tube-time in exchange for allowing me to choose from 1 of 3 abilities. Some skills are obviously useful (like Rapid Fire or Rupture), and others can entice interesting builds (after getting Kill Zone on a Ranger, I decided to give her an AR and a Sword Build, for mixed Short/Long Range options), and then there are the ones that are just useless. My Sharpshooter got Salvo, which I'm struggling to find any use for (Snipers can't use it at all, for several reasons, but even Gunslingers already have Quick Draw to Shoot and Grenade, if they wanted to do that). I liked the way the Long War AWC could help encourage unusual class builds, with the right combination of abilities.
On items. Personally, I'd really like the one-grenade per soldier limit to be removed in Vanilla. It's only applicable for T2 and T3 Medium Armor, and essentially ignored for Heavy Armor (since you can bring a grenade and a heavy weapon). Now, Grenades are stronger in Vanilla, so that might be a bit over-powered. But I wouldn't say no to more readily available items to put in the second slot. The only unlimited utility slot item is grenades. Ammo is the most obvious choice, but those take a while to build, and you won't always get what you want.
Vests need to be changed to their Long War 2 versions. I have never used vests in Vanilla and see VERY little incentive to do so. Yes, they'll become flat up more powerful, but that's pretty darn fine considering how weak they are in vanilla. With only 2 slots (or one if using Light/Heavy armor), who can find room to fit in the +1 HP of the Nanoscale vest? You've got too few slots to spare, and too many things to use in them, to really justify dedicating 5-10 days of Proving Grounds time to get a random vest. I don't mind random ammo so much, as every piece has it's value in a party. But the vest are too situational. Especially Hellweave.
Lastly, there's single items versus squad upgrades. Ironically, I feel that these games have things backwards. Sort of. I don't feel I need to purchase squad upgrades in XCOM 2, because I'm not dealing with that many soldiers. Why by Sniper Rifles for a dozen people, when I've only got one Sharpshooter? This leads to the rather bizarre situation with Rangers. As soon as I get Mag Weapons, my Ranger puts down her shotgun. The Mag Rifle is better in almost every respect than the Ballistic Shotgun. And the Mag Shotgun is only really a side-grade to the Mag Rifle. As such, purchasing the Mag Shotgun seems like a low priority. With my main Ranger having Kill Zone, I ended up skipping the Mag Shotgun altogether.
The issue gets even weirder with the Hunter Weapons. I've got two Sharpshooters. One is a Sniper, the other is a Gunslinger. So I upgrade my Shadowcaster, but my Sniper still only has his ballistic revolver for whenever he needs to use his gun (as a follow-up from Death from Above, for example). At this point, I could upgrade the basic pistol as well, but then I'd be paying squad-price for a single weapon. The necessity of Squad Upgrades, rather than single purchases, is also part of what hurts the Vanilla SPARK so badly. Even if you get one for free from the Lost Tower on a flawless victory, you still have to pay a small fortune to keep their gear up to date. With one of each base class as well as a Psychic and a SPARK, you've bought squad upgrades that are never used by more than one soldier at a time. 5 sets of primary weapons (or 5 sets and the upgraded Boltcaster if you use that), 5 secondary weapons (6 if you count the SPARKs BIT), and a hodgepodge of armor, with probably only your Specialist using the squad-wide medium armor upgrade (if you didn't skip it entirely).
On the other side of the aisle, when I'm managing 18+ soldiers, having to constantly dig around for where I put those Predator Suits, or whatever. Squad upgrades would be far more useful here, and yet, they're not an option. Prices might have to be changed to be more appropriate, but somewhere around the cost of 3-5 of a specific weapon. Sure, you can have infinite laser rifles... but are you going to use those on your Assaults instead of Shotguns which you didn't mass produce? And what about the classes that usually use SMGs? Are you going to give them Laser Rifles, or keep their Ballistic SMGs? What about buying EXO or Spider Suits once you've mass produced Predator Armor? Mass Production could be priced such that it's cheaper to outfit your entire army with a specific piece, but you'll be less able to specifically tailor your gear. Done well, it'll add a bit of meaningful depth to the choice for experienced players, and casual players who just want to not micromanage certain things can take it for ease of play.
Anyway, those are my thoughts about what I think should cross over from one game to the other, whether officially (come on next DLC, Firaxis!) or through mods, some of which I'm sure already exist. Aside from all that, I've been enjoying the somewhat more relaxing Vanilla game, where I don't have to gear up new missions every couple of hours of in-game time. Pods seem smaller and less densely packed as well, so I don't feel like one bad flank-attempt will ruin my mission by activating another 4 enemies. That's all a design difference of Long War, though, so I don't really think it fits the spirit of the thread