My opinions of the X-Force alts: I think I'm going to be abstaining.
I think there are only really two situations where I'd consider getting them:
1) If I had most of, if not all, the heroes already available.
2) If I regularly ran a team with any two of the five heroes with the X-Force team up buffs.
Neither of those apply to me though.
You only get additional benefits (as I understand it) from these alts if you take two of them (or Archangle or Fantomex) into battle [though why I went up against a PVP team today which had only one hero with an X-Force alt went over my head, so maybe there's something I'm missing...]. Since I don't regularly take a team with two of those heroes that means they have very limited utility for me.
120 to 150 CP (180 to 225 for the whole set, not including Archangel) is a lot for alts that I'll likely get very little use out of. Right now, for me, I think that CP will be put to a lot better use towards heroes I haven't got yet (especially with the Shanna CO being so CP intensive). I'm in a position where I need to be farming and then saving for the next SO [and the next CO, if it's anything as intensive as this one].
There are some interesting buffs in these, but not significantly more interesting for me than E-Isos - at least, not significant enough to overcome their expense and the fact that E-Iso have a lot more utility.
These teams might end up making strong PVP teams, but even in that case this is a very versatile game, and I'm sure I can find a way around it. If there's one thing I'm sure of about MAA it's that there's rarely one right way to do things - there are different ways that suit different players, and you've just got to find the way that works for you, the way you maximise your potential within your means.
If they had included a new individual buff for their respective characters I might have been tempted (I like using Wolverine, especially, so something to add to that experience would have at least been worth thinking about). But as it stands I wouldn't get much use from these anyway.
It's sad to skip on the option to class switch Deadpool and Psylocke - but it's just not worth it. And I'm sure they'll become permanently available eventually.
Overall, I think this is mainly a release for the upper league players, those who've already got most of what there is to get. I expect there'll be a lot of people in the same boat as me, foregoing these in favour of recruiting more heroes and especially in favour of completing the current CO and saving for the next SO.
I might be made to change my mind if I start getting obliterated by these teams in PVP, but I somehow doubt it right now.