It would seem to me that if the current unit did a good job for 21 years, replacing with the same thing would make sense. However, if there is performance considerations that the old one didn't impress at and other models do better then look elsewhere. That being said, if the complaint on the current one is that it is slipping while in-hauling, then it is probably just needing a new gypsy and pressure finger spring. Also check to make sure the finger is not bent. If you post the brand and model here, there are guys here that can give some good info.