im not saying a gear diff is the best performance option going..
But a gear diff i feel is easier to keep consistant even with having to change the fluid ever other race day... 4000k oil is always 4000k oil when you fill it up fresh. Rebuilding a ball diff wich i am very experienced in.I know how to buid them, but the effort involved is just not worth it for my level of skill and commitment
Cheap and lazy racing
LIPOS and BRUSHLESS motors are to blame... Used to have a 12 step process just to get nihm and brushed motors ready.. LOL