I'm satisfied with the Isolation Alien we got but I do understand the annoyance. The figure is far from perfect. I couldn't resist from tampering with it, starting with a dome repaint. Then I modified my alien and gave the arms a revoltech joint so the elbow bend goes well passed 90, but the fact that the head can't go backwards fully is very irritating.
The neck/head articulation needs an upgrade for the Big Chap and '86 aliens. The blue frosty Kenner big chap had the new double bend elbows and the new knees which are awesome, the 40th anniversary alien will have that as well, but the neck needs more range, a lot more...
I'll probably do a slight repaint of Stompy eventually, but I really want to make that head go backwards. I have a plethora of revoltech joints that could help but the problem is I have no idea how the head is attached inside. Maybe I'll just try by making a cut/gap into the back of the headsculpt for I believe that's limiting its range more than the neck joint at the moment.