Well, not exactly as i won't delve in class balance or dark events, a lot have been already discussed. Instead i want to post my own experience about one very specific aspect of the game, corpses requirements for both autopsies unlocking some items and producing those items, and especially late game corpses.
I think switching to mostly evac missions was a wise move from Pavonis as having to kill "every" ADVENT guy in most mission when you are supposed to be a small band of rebels trying to make quick strikes in enemy territory always bugged me. However it have introduced a fundamental and possibly hard to solve balance issue when combined with the corpses required to build many items.
In my first quickly abandoned run i had almost no Stun Lancer corpses to build better swords for my shinobis. It's been much better this time, i even managed to get enough of those for instant autopsy and then of course i had a stock for swords. This finished run however, i ran into another issue with late game autopsies and the items unlocked. Specifically, 2 late game enemies were very hard to encounter in ambush missions, and i ran a lot of those to the point i slowed Avatar by more than 100% at the end and the doom counter was at 4 "pips" when i finally invaded waterworld. Those enemies were Gatekeepers and Andromedons. I managed to autopsy a gatekeeper in December after specifically taking a late game HQ in hope of facing those 2 enemies, but the first Andromedon corpse i recovered was in February second year! I barely finished Advanced explosives and Fire Bomb in time for waterworld but no other post Andromedon project and never got a second corpse to build a single T3 Holotargetter.
This had an impact on the late game performances of several of my soldiers. My 2 Psi of course suffered from the lack of T3 Psi-amp for a long time especially since Psi-amp tier seem to have way more impact on their abilities than their Psi Offense. After T3 Psi-amp i finally had good probabilities on Insanity (up to 90% on ADVENT and 100% on Aliens) and good damage on Null Lance, but it was so late that i could have finished the game had i not taken my time to progress through the storyline missions. A lot of the "Psi Troopers sucks" argument would probably disappear if T3 Psi-amps were actually available before the campaign is finished for many players! Of course, out of my 2 Filed Commanders, i didn't choose the Holotargetter one to lead the final assault without a T3 Holotargetter.
February was way too late to get this first Andromedon corpse, many players would have finished (win or loose) before and an entire branch of Proving Ground projects depends on it. I had faced them for months in evac missions, but never in ambushes.
Similar issues can occur during the campaign. You will eventually get some of those corpses, but sometimes after a long time. Having the secondary upgrade delayed while they are already less frequent (3 tiers instead of 5 for primaries) can really hurt some builds.
If possible, it would be nice to have some check when spawning pods so that after a new enemy appeared, if the player have not recovered a given number of corpses, that enemy is forced to appear on non-evac missions. It doesn't have to be very high, something between 3-5 so you can make the autopsy and build a few items but you are not offered the instant autopsy each time.
