Vibrations and noises are VERY difficult to troubleshoot long distance, only having a textual description to go by.
As far as the driveshafts in these cars, they are actually quite reliable. The reason for this is the fact that there is no up and down movement of the rear differential yoke as there is in most cars without independent rear suspension. The most common problem is the rubber flex discs that deteriorate with age. Most likely you could have replaced a flex disc rather than the entire drive shaft.
Sorry I can't be more helpful.