I have Nitro gears in my 8.8 and HP30, no issues during set up and are dead silent. I was impressed enough that when I decided to put chromo shafts in the HP30 I went with Nitro. $450 from ECGS and carry a 10 year warranty just like the Superior Discovery shafts.
I also believe if you purchase the Nitro D44 front shafts through ECGS with upgraded u-joints they will warranty them for life.
CU Boulder Aerospace Engineering