What things have you heard about loading TSX's?? I have been loading them for a number of years and nothing bad to say about them.
I can't see your groups site is down but if it shoots well give it a go! I personally used 140 tsx out of my 7mm rem mag for moose and elk with superb results. Deer I prefer the 150NBT, deadly accurate and on game as well.
120BT at 3500 fps wouldn't be my choice for game, I'd lean towards the TSX if he is stuck on the 120's. I used to think speed and light but I'll give up that front end speed for down range performance now.