I have not ridden either board but did a ton of research on both and just ordered a TRS. I will ride it for the first time on Friday. I am boot size 7 135lbs and 5 6. I ride a 147 pickle and ordered the 148 narrow. Anyways for you:
The hot knife is going to be stiffer and an aggressive all mtn board. It is C3 technology which is primarily camber with a mild rocker between the feet so it will be much less playful and less forgiving than the TRS. But I see you have been riding camber so you may like it.
XC2BTX has more rocker than C3 so it will be a looser ride than the hot knife. Reviews say the TRS rides stable for a rocker board as the camber sections were extended this year. I am going to use the TRS as my all mountain board and my Pickle as my jib/pow board. The TRS will perform better in powder due to more rocker but probably not deep powder.
They make the TRS in narrow sizes 148, 151, 154, and 157 but with a size 9 you should be good either way with either board.
I like the looser skatey feel of rocker but wanted an all mtn board that was more stable than the pickle and could fly down groomers but hit natural features at the same time. The TRS will have more flex than the hot knife and will also be more forgiving. It will also perform in a variety of conditions (hardback, pow, etc).