In regards to the Quad .50 trailer, I think it is actually a well-done piece for what it represents. It seems everybody's issue is that 21C should have picked something different; but I don't remember any complaints on its actual executiion/details. The spot for the figure is super-small, but I think that's fairly accurate to the original, and I think 1/18 plastic just doesn't bend/compress like the real thing enough to wedge a person in there.
But I can't disagree on the M113 crewman - I finally threw away the body and legs last night; I saved the head/boots/arms/hands for parts. But maybe even then... That whole series from 21C (afghan fighters, royal marine, spec ops) were of a noticeably decreased quality. They must have lost some important talent that took too long to replace.
As for the In-Toyz guys, the head sculpts were always weird, and the arms/hands chunky on some. But I thought the gear, and sculpting/details on figs like the SEALs was generally good.
I thought the BBI "British" figures (
http://www.sshqdb.com/18/index.php?cat=120) were lame, not because the figures were so bad, but because they just took their US figures and repackaged them. As British figs they are obviously horrible representations (kind of like taking a so-so P-51, repainting it, and then saying here is our "Real As It Gets" Spitfire
), but if you ignore the "British" part they're ok I guess.
Another example of that is 21Cs attempt to re-package their P-40 as the Sky Captain movie plane (
http://www.sshqdb.com/18/index.php?cat=75). Except for it being painted black and based on a P-40, it had almost none of the distinctive features of the bird in the movie. Again, a lame attempt to reuse something without bothering to even change a few essential details. Their support of the Sahara movie suffered the same types of problems.
Still, these are pretty much the exceptions in what overall was great product from 21C and BBI. Admiral did great vehicles, and even their president agreed their figs had major problems, so it's almost too easy to pick on those