A visual indicator on health bar for when a player is at or near max overheal. Reading numbers or looking at the size of the cross is difficult to do when firing into a crowd.
Rejuv healing buddy no longer reduces allies uber charge rate. Other mediguns are already punished by stealing the healing but do they really need reduced uber rate because another medic is splash healing?
Make the hit sound quieter. Medic is a class who must constantly be aware of his surroundings and teammates. Massive "bonk" sounds every shot makes it harder to hear what your team is doing.
Direct hits play a different sound. This is to incentivise accuracy and allow tryhard medics to feel bad about near hits.
An ingame tip advising players to stand next to teammates if they want healing from rejuv. I found this change in medic/player behaviour interesting but it didn't last very long after update.
Changes to uber generation:
Uber is gained passively but down scales with the time since you last healed someone.
Builds slower than stock.
It's important to note that in some situations, the rejuv uber is stronger than the other ubers. Annoyingly, those situations tend to also allow him to pump out massive healing and build his uber faster than a kritzkrieg. It seems unfair that a weapon has more healing, more range, more uber, and more fun. Another issue is that any player who stops shooting, either because he wants to save some shots for emergencies or look behind for spies will suffer a noticeable uber build penalty. While other mediguns use uber rewards to force them to heal smartly, the need to build uber as quickly as possible can distract rejuvenator medics from taking the time to aim properly or make good decisions.
My intention for all these changes is to make the rejuvenator into a more intellectual playstyle rather than brain numbing spam.