RP23 transformed my mega. bike feels so much more how it should compared to the RT3. i'm trying to think of ways to describe it without sounding too cliched, but the back end just feels so much more active - it tracks over rough ground better and certainly has added more 'pop' to the bike, making it feel more playful.
i'm not even sure it has the correct tuning, as i just did a cheeky swap when i bought the mrs a new frame (she will never know!). it feels like it is going to blow through its travel though without any propedal, but it rarely pops the o-ring off the end of the shock though, so must be alright.
rebound adjustment is substantially better. i like quite a fast rebound and the RT3 could never quite provide what i needed, but the RP23 does - perhaps why it has more 'pop' as i mention above.
propedal beats floodgate too.
just a much better shock in my opinion.