The FXT was a good bike in its day, but it's heavy and the frame design around the rear suspension means it fits more like an 18'' frame...which is not good when you're 6'4''. I've been running a very long seat tube to compensate, but that just creates new problems; particularly putting lots of leverage on the rear suspension, which I've had to virtually lock to keep from losing too much crank energy--effectively rendering the whole mess a lot of dead weight. The front shocks have also seen better days and don't really dampen so much as shudder and jolt, plus you've got to flip the bike over and pull out an allen key to adjust them.
The Zed is a nice change, from a bike that's really too small to one that has enough saddle adjust to fit someone even taller than myself. There are a few upgrades I've added to the KHS over the years that I'll transfer to the K2, but for the most part it's a solid all-around upgrade. I'd like to step up to Deore shift spec eventually, but for now the bike will do just fine. It has Hayes mechanical disc brakes, Rock Shox Dart front fork (with preload adjustable on the fly) and basic Shimano shift spec right now.
Here's a nice stock photo of the model:
i used to have a K2 ZED, I liked it alot until the rear hub went out with only 200 miles on it. I bought it at d!ck Sporting Goods with a protection plan, they said anything broke within 2 years theyd fix it for free, as well as 2 tune ups a year all for $69. The one guy that worked there had a level of paralysis from a downhill biking accident(he competed). Thought they knew there stuff however after 2 months they couldnt do anything with it and they gave me a new bike. A diamondback. 
I had them transfer as many parts from the old one to the diamondback like seat and tires but the front fork sucks compared to the K2.
If you know what i mean.