so far grooves 6.5 is kicking ***! I flashed the stock sprint rom, and then 6.5 with absolutely no issues. I didnt even have to remove the battery during start up.
I get a slight hick up while texting every now and then, but honestly most other 6.0 roms still are experiencing some freezing up issues, so I'm not too worried about it. Grooves 6.0 roms were the first to fix that issue, so I'm sure he'll be able to fine tune any tiny issues that may arise in 6.5.