I'm sort of a newbie to mtn biking. I got a Haro hardtail, aluminum frame, some LX parts on it. It was fine for what I do. Then I got a Gunnar Rockhound steel frame on ebay. My bike-mechanic BF moved all the parts off the Haro onto the Gunnar. The ride on the Gunnar is a huge difference. Maybe it's the geometry (these are both xs frame sizes) or the steel vs aluminum. The Gunnar climbs and decends so much better than the Haro, though I'm still a chicken.

My BF recommended the hardtail. He has a Klein hardtail (he is jealous of my Gunnar ) (He wants a Gunnar now). He thinks a full suspension would be more maintainance.

But a while back, before the Haro, I did try a Jamis Dakar full suspension bike and I liked it a lot.