I've had/have them all... I have a CTS and I have actual gauges.. I've had a dual pod and triple pod now.. My suggestion will be based off of your needs..
If you are just running a mild tune, etc.. get an Autometer EGT and Boost gauge in a dual pod and be done with it..
If you are one of those guys who wants to know the temp of your air intake, etc.. mostly stuff that most don't care about, get the Edge unit and monitor it all..
Keep in mind if you get a triple pillar setup.. I can almost guarantee you will crack your head/face off them all the time, and your sun visor turns into a PITA.
2010 Yukon XL 2500
with LMM straight piped
EFI live tuning by Duramaxtuner