I've got the Maximus AVR 1.0 (the first version without the casing). Currently my manager of choice is the Gaia Manager V1.03.1 [currently 1.04.1 is the latest] and the hex I'm using is PL3 psgroove. Sorry not sure of the actual hex but it was the one from the Gaia topic thread. It was the one that ran Medal Of Honor - and also is able to boot COD-BO.
It's personal choice, depends on what you want to do with the app. For me, as long as it works, I'm happy. I'm still using the original PS3-FTP app [works great with direct connection to PC - PS3]
Good luck mate