I have done a valve body rebuild with alot of parts. I have to say honestly, if you have no shift issues, don't do it, the difference is negliable. If you have a transmission with some miles on it, go for a full rebuild.

The best way to go is let a shop rebuild your VB. The only way to know if something is bad, is a proper pressure test bench which we as hobbyists don't have. Trust me, I can do this myself no prob but if I look at the hours I spent, part costs etc., next time, I will drop my VB at a specialist or just buy a BRAND NEW ONE from ZF.

Only exception is the 5HP30 check ball fix since this is a known issue.