Re: X-Men First Class v.s Captain America TFA
There was nothing rushed about CA.They can (and I'm guessing eventually will) revisit the WW II era eventually.(Baron Zemo!)
As for FC,in a way it did feel rushed to me,but I think not to have Charles disabled that way would've lessened the impact of the films conclusion.So I can't hold it against them,but I think it might've been handled better.
We always need to hear Both Sides of the story.