Okay, some background. I bought a nice (to me) MTB about twelve years ago for about $750. I loaned it to a friend who treated it like a beater, and I kinda got out of it for a while because I was sinking a lot of money into repairs. Suspension wasn't an assumed feature on MTB back then, and while I could have bought a bike with cheaper components and a suspension fork, I decided I didn't need suspension. I eventually fixed the bike back up, and have repurposed it as my commuter. I have the itch to buy a new bike of some sort, and one of the things I'm thinking about is a new MTB with suspension. Today, it seems suspension is assumed, and that the kinks are fairly well sorted in the sub $1000 bike suspension systems.

I've tried about a half dozen bikes, with prices as low as $560, and as high as $1050. Compared to my old, non-suspension bike, everything I've tried seems soft, slow (no off-road test rides), upright, and plastiky. I'm trying to keep an open mind, but at this point, having tried and hated a bike over a grand (08 Rockhopper Comp Disc 29er, IIRC), I'm starting to think that the problem is me. (Yeah, I'm open to that.)

So, my questions:

1) When you moved from non-suspension to front suspension, did you get this same sort of problem?
1a) Did you get used to it?
2) Should I be looking at a certain bike? I've tried a Gary Fisher, a few Treks, a Giant, and a couple Specializeds. None of the shops had anything in those lines that they thought would work for me. I just want something that has a firmer suspension than what I've tried, and gives me a position less like that of a cruiser or comfort bike.

For what it's worth, it's not very hilly or rocky here, so I tend to deal more with ruts, tree roots, and mud.