the reasons typical rebuilts are a poor risk is, they grind the carrier
until the pits are gone and drop in new oversized ball-bearings. But,
they are also grinding away the case hardening. Couple that with the
likely cheap bearings and cheap grease and cheap boots...well, the risk
starts getting high.
many folks will get used Subaru axles from a junkyard (car-part.com)
and rebuild them with new grease and boots. I would prefer new axles,
even if Chinese, to typical rebuilts.
I caught my OEM axles just after the inner boots split so, I used a
Beck-Arnley boot kit and cleaned and rebuilt them. But, that is risky if
the boot has been split for months/years. Outer joints are even more
risky if they have been exposed for a few days/weeks. Inner boots fail
early from exhaust heat.
But, if you have clicking/thumping - probably time to replace the axle.
some folks report good experience from Raxles. I don't know if FWE/MWE in Colorado is still an option anymore.
the 'best' option is new NTN axles from Subaru - but $$$ .
If you don't mind the DIY approach, reboot some axles from a wreck -
inner 'cups' should be green - probably stamped NTN somewhere.
My personal recommendation if you don't want to do the above, get
highly rated new axles; FEQ, EMPI or similar from autozone, or rockauto,