I have a 2610 and wish I had bought a 3310. The 2610 with a 6ft RFM can't make it up a minor to me grade and maintain PTO or forward speed. I sold the RFM and bought a ZT. Certainly the best solution, but also much more money that could have been avoided with enough tractor power. Would the 3310 have been enough for my situation, don't know, but likely would have been sufficient. Very dependent on your terrain and use.
Will wind up buying a very light 5 ft knife flail for the tractor to handle the parts too steep for the ZT. Already slid the ZT through one fence, fortunately no damage other than to the fence.
On my land I would never buy another tractor that didn't have the maximum HP available for the specific frame size I was purchasing. This would not be the case if I still lived in Illinois where it is fundamentally flat. On flat ground the 2610 handled the RFM no problem. A cabbed 2610 would be even more limited in this regard due to the added cab weight.