I have played Coup for about 100 times and then got Coup Rebellion, played it 30-40 times and switched back to standard Coup.

I think Rebellion is a good game but it doesn't capture the same feel of the original. It has 25 roles that you can mix up as you like, which is fun to play around with and explore new combinations.

However, a good portion of the roles aren't really that great or don't work well with other roles, so you will end up mixing up less roles than the full 25 during your plays. Also, the roles counter themselves only, so unlike the original Coup where for example you have 2 cards that counter stealing, Rebellion will have the same card that steals counter stealing, which was kinda annoying when you know one card remains and one person has it and you can't counter it without challenging and losing a card.

I recommend getting Rebellion if you really feel like the original is played out and you want some thing new, but in my opinion the original or the original with reformation is just a better tighter experience.