I run 5on5 adapters on my Dana 30, have been for three years now. I haven't had any problems myself.
The only PITA is if you need to take off the Jesus nut, you have to take the adapter off to get to the cotter key.
I run them with JK steel 16" rims and 33's.
'95 YJ 2.5L "Mabel", Muncie SM465, np231J, HP30 TJ shafts, JK D44 Detroit, 4.88's, 255/85r16 KM2's, SUA lift, body lift, JK steelies, winch, flat tow bar, CJ/M38A1 front clip, CB, Bestop seats
'98 Lexus LX470 UZJ100 black trim and rims, 4.7L V8 4spd auto, full time with center diff lock, open 4.30 gears, 31" Yokohama HTS, AHC delete, TJM torsion bars, 80 series coil springs with 60mm spacers, custom shock setup
going to EJS 2014