I can’t comment on the carbon frame but I’ve got an alu framed 2008 Rush. I’ve owned it for just over 2 years.
I’m also 5ft 11″ (well just a fraction under!) and I’m comfortable on the medium. Size large ‘dales always feel too long for me.
As to the ride itself, I like it a lot. It feels like a playful bike when you want it to, no hidden surprises. I use it for any length of ride, just a general purpose MTB. I am lucky enough to live surrounded by Welsh trail centres, and have a few DH style tracks on my doorstep, and it handles everything I throw at it. I would be happy to buy another if I broke this one.
Dirt mag thought it was a good bike, as did ST. WMB didn’t like it much because it’s an old fashioned design of suspension iirc – insert raised eyes smiley!