Thermage for Upper Arm Flappiness? (Photos)

In my experience, Thermage can help with the loose, crepey skin that often occurs on the arms as well as the knees.  I have found it to be very impressive in treating the flappiness (bat wings) that you describe.  Surgery is an option, but there is often a prominent scar after an arm lift procedure.

Thermage tightens loose skin but does not treat the deeper fat.  It would give you some skin tightening, but from your pictures it looks like you have more of an issue with the underlying fat and perhaps muscle tone.  The best option if you want to avoid the scarring of surgery may be two Thermage treatments and additional exercise.
 

Thermage will help to some extent and I stil believe it's the best non-surgical option, but the results can vary and it usually takes a few treatments to treat sagging skin on the body. Treatment should be done by a trained aesthetic physician or directly under their supervision for best results.

You are wise to research the efficacy for Thermage.  Given the excess fat in your upper arms, I would not consider this the treatment of choice.  Thermage produces small reductions and tightening.  It may be a good adjuvant to a brachioplasty or liposuction of the upper arms but I don't think it will give you the desired result and would hate to see you spend money on it, only to be disappointed in the result.  Best of luck!