The OE volvo parts are more precision, I did not need a press for my center bearing but two previous FCP Groton center bearings did need a press to get the bearing into the support. Replace the bearing rock guards as you destroy them unless you use a press.
The aftermarket U-joints are not as beefy as the OE parts, after I crunched a few rollers I went back to the OE's
I work for Clevite Engine Parts so I believe in aftermarket parts it's just that sometimes the will-fits are not as good as OE.
I buy alot of parts from FCP and think they're great and will not complain when the problems are ones I created. Good luck!