Horrible advise, turbos should ALWAYS be balanced after a rebuildI rebuild turbos that arent that bad. Pretty much what I do is, mark the turbines to a spot on the bearing (center) housing before I remove them. Pull it a part, replace all the parts (o-rings, bearings, ect.) Line the marks back up and bolt the turbine back on.
Balancing wouldnt need to be done unless you upgraded the cold side turbine, or didnt mark lines first.