Why?
I've never owned a dual suspension bike but I may, if things go all right business wise, have some money next spring to buy one more decent bike.
I started trail riding in the mid 90's on a rigid GT Talera (before that it was BMX) and since then I have owned a Cannondale CAD3 which I built up myself when I wrecked the GT. Cannondale had a trade in deal and I think I got the frame for like $200. I rode that for a few years and then bought a Stumpjumper hardtail in 2000 which is now my SS. After that I owned a Giant Ranier and now I have a Mongoose Amasa Comp which is only a couple of months old.
I still own all of those bikes which really makes my wife mad at times. 
Anyway, I've been thinking about investing into a top end bike but want to make a well thought out decision. I kinda rushed into getting the Mongoose because I needed to do some much needed work on the Giant and I got a good deal on it but.
What trails do you guys find double squish provides a noticeable improvement? Bear Creek maybe? I rode the Mongoose there and was okay but maybe full suspension would have provided better handling.
What do you think?