I have an ANS LP front block, and I have not had any probs with it. If I don't allow the trigger to come all the way home, the four-way will hiss. Then again, I have only experienced this while tinkering... never in a game.
I also have an ANS shroud. I like it. It looks way better than a stock shroud, and it's rubberized for a sure grip. I know... Most people probably don't use their shrouds. So be it. I just don't want to hook a line on a twig and have it come flyin' off. It also makes for easier clean up.
I don't have any problems with Palmer and Shocktech. I've only heard good things about their products. I just feel that ANS got a bad rap back in the day. Perhaps their products were sub-standard then. I haven't seen it.
Line SI Bushmaster Deluxe
M3 Black Dragun LCD