Hi Keith:
I have a 2720 SD with the larger axle and 15" rims (plus two lift kits) and am very glad that I did it. But there are things to consider, like the overall height of the TM for storage and the "bounce factor."
I'm too sleepy from my most recent TM trip to discuss it right now, but this has been discussed at great lengths elsewhere on this forum. Check the "Bigger wheels? Heavier axles?" thread in the Towing Rigs section and the "5000 lb axel" thread in the General Discussion section.
I'll see if I can post links to the threads below:
http://www.trailmanorowners.com/foru...=bigger+wheels
http://www.trailmanorowners.com/foru...t=bigger+tires
These two threads should answer most of your questions.
Enjoy!