[notorious_benny]

Vic 3D, I have the super xtra with approx 70 flights on it. I can tell you it dosnt do any 'weird' snaps for me, my primary focus is IMAC flying, I fly in the Advanced class. It is a very, very good sequence machine. If you take the time to set up your thrust lines correctly it has very little knife coupling. About a 6% mix from memory. It also does not have any strange roll charactaristics.

I am using the 3W 157CS on cans in my super xtra, this has plenty of power to pull the model through the Advanced sequence. The super xtra is a noticebaly larger airframe than the 260, and a lot more draggy, I like this trait for IMAC flying as the up and downlines are all at a nice constant speed giving plenty of time for all the elements in your sequence.
The other nice thing about the 3.1 is the way it spins and stall turns, get it right and it is very graceful and adds that wow factor.

I have flown the 260 as well, only for a short time, it is a very straight flying machine as well, I did find it more touchy around the roll axis and that it flys faster as well, but with the right radio/model setup would most likely be just as competitive.
Also from some the guys I have spoken to flying the 260 it also needs some mixing for knife edge.

You wont be able to go wrong with either model as they are both great (from composite-arf of course!), however I will vote for the super xtra because I have one and think its a nicer looking model. That was the final reason I purchased it....... real scientific huh!

Heres a few shots of mine...............