I'm playing commander/ironman and so far its been exciting into the lategame. I thought I was playing efficiently yet I still fell behind the curve at one point. Now I've got a couple psi ops trained up and plasma rifles and things have stabilized, but its still not a done deal. I've got some truly horrifying dark events running: Xcom doesn't start concealed and chosen have no weaknesses. The lost are growing as a threat instead of shrinking, the dashers spawn with 7-8 health and single dashers have hit for *4* damage. The fields are swarmed with powerful mechanical and psi units. I was too worried about wounds to do facility missions so for the first time ever I found out what happens if the Avatar pips fill up (which is really awesome BTW, its like 24). I'll Assume I don't get any more second chances there; but its almost filled up again, a lot of the A team is still wounded, and both me and the assassin are ready to attack each other. Basically shit is still tense when it should be trivial. If I hadn't augmented the B team with overpowered psi ops, I might have actually lost an entire campaign maybe 20-30 hours in, via normal gameplay with little bullshit. That's... a change, for sure.
What's weird is I feel like I was pretty efficient both leveling up the squad, and researching tech. I mean I did the new autopsies and got psi + some breakthroughs, but... aside from that I pretty much rushed down tier 3 weapons/armor with a lab and it STILL felt like I couldn't get my soldiers upgraded soon enough. And I didn't lose anyone until elite MECs and Andromedons started appearing, which is quite lategame. I'd say these are probably why the campaign is still interesting:
1. I chose not to do the sabotage covert op (automatic -1 avatar progress per month) on the grounds that it would make the campaign trivial. Ditto for not building mimic beacons. And I avoided spamming the "reduce avatar progress" covert action more than a couple times since it feels cheap.
2. I got psi ops late. They're definitely... still a balance problem. That's not why I got them late tho, I just didn't feel like it was worth the money/research time in the early vulnerable stages of Xcom.
3. I rushed the GTS and training center immediately. I'd have to say this was a mistake. They both seem like buildings that are best when Xcom is already established.
4. I didn't build the infirmary, and in fact don't have the room to build it. This is a big one, the infirmary seems like it would shift the game into a more base-game mindset of having 6 colonels. I also avoided using orders to make the squad recover quickly, although I caved and got the 20% will recovery one because tiredness was becoming a problem.
Overall, between the dark events + sitreps, the lost, the chosen, the rulers, the different mission types, the varied enemies the base game already had, the fact each mission I bring different types (and even numbers) of troops... this campaign hasn't gotten old yet. And I find *all* Xcom lategames boring including oldcom and xenonauts. I have to say tho, especially without a WOTC "skip gatecrasher" mod, I'm not sure I'd want to play legendary. I *like* being able to make risky moves and still come out on top, the idea of having to play an even longer campaign AND have to be uber thoughtful every move doesn't sound like a fun time. I'm considering playing an "all dark events are permanent" run on commander, but some of them (lost world, no concealment) seem like they would be less "difficult" and more "tedious and repetitive." I'm thinking of other self imposed challenges or mods/mutators to do, preferably with a focus on lategame difficulty. I'm not sure the chosen will have any longevity for future campaigns; I already kind of groan when the assassin appears. The warlock seems better designed, the hunter is cool but also kind of trivial and his animations are on the long side.