I think there must be benefits to both, but from what I’ve read the healing process and final result with unders is long, ( I’m nearly 3 weeks post op with unders and I’m happy and mobility is pretty much perfect now) .. But things such as breast feeding, easier mammograms etc are a benefit.. But I had no boobs at all! So had no choice so I havnt looked into overs at all.
I do believe the surgeon knows what the best look for you is, but if there are reasonings behind wanting to change I would look into it all first or chat with him/her xxxx