I demo'd a bunch of LibTech/Gnu boards last winter and one thing I got out of it is that the hybrid camber boards have a greater useable range per a given length. I'm 5'10" and weigh around 170 and prefer a slightly longer board, I have a 160 Jamie Lynn. But I mainly just cruise groomers or hit the steeps on powder days.
Most of the guys who were at the demo booth were about my size and much better riders but had generally downsized their main boards to 157 just because the versatility of the new designs, they could get a shorter board that was more playful but could still set a carve and float in moderate powder.
I think it would come down to where you will spend the majority of your time. If it is carving and powder then go long. If you like to play around in the park, run through trees and generally like a more maneuverable board go short.
The TRS is, or at least was, a more centered board so isn't the greatest for powder but the hybrid cambers float a lot better than standard camber boards.
Also check the board width and see how that relates to you shoe size. You don't want it too wide or narrow.