If you are comparing next years Heritage to previous years, don't bother. It has the same name that that is about it. I am 6'2 and btw. 175-185 lbs, I have ridden the following NS boards: '09 Evo 158, '10 SL-R 164, '10 Premier 163, '11 SL-R 158, '11 Heritage 158. The closest board to the heritage is the SL-R. Riding them back to back, to me the Heritage is a slightly beefed up version of the SL-R but is also lighter and more nimble. It is definitely not a jib board and probably not the best park board, but then again it geared more towards all mountain freestyle. You can take this thing anywhere, hit big jumps with confidence, ride in pow, and so on. I do agree that NS boards are, for the most part, beefier and more stiff than other manufacturers. That is why you get such a good warranty.
As for the OP, you really are talking about two very different boards. I will say this though. If you are 192 and on a 155 Evo, that is a pure park board. Coming close to that weight on my 158 EVO I definitely have a little trouble in chopped out snow and I have to work hard. I would trade in for that reason alone. Just realize the Heritage is not really going to do it for you as a pure park stick.