I like the QL series tractors. Of course I'm biased, I've got a 1650. As best I can tell, the thing that turns off most is ISO mounts get squishy and need replaced. I don't consider this a big deal. Other than that, I feel they are a very good tractor. I like the looks of them too. They strike me as an interesting combo of new and old. They are definatly rock solid/heavy duty, but were the first Cub Cadets to have an enclosed engine compartment and electric actuated PTO.
I think your 1250 is a fine machine - keep it!
Also...
Good luck,
Bill