I personally don't like topps letterman the only good cards as said by "jordan23" are the 1/1s that are game used, the other ones are just manufactured. Save your money and buy Ultimate or SPX.
Too much manufactured crap in these. Amazingly they did put a couple of Game Used 1/1s in their, but the rest is as good as base IMO (as manufactured is the same a normal manufactured piece of cardboard card).
Save your money and bust something like SPGU, Perhaps Ultimate.
Theres a few people on this site that should be able to source a box of SPGUs, i buy from westriot since hes located in sydney, and is top notch for delivery times and communication