VoidUI (not de googled) because:

1. the main reason is so I can keep using my phone beyond the official SW support period, I would be stuck on A10 if I stayed with stock
2. The phone started to feel a little bit slow after 2 years
3. Unlocked some of the performance that was left on the table with more to be unlocked!
4. No bloatware

The drawbacks:

1. The camera experience is orders of magnitude worse
2. Goodbye iris scanner :'(
3. Goodbye S-Pen features
4. Goodbye Samsung notes
5. Goodbye to the much better split screen and floating window implementation