Get one, you won't be dissapointed.
They've got the sport lights at the front, electric sunroof / windows, air con, alloy bonnet, some seem to have leather headrests. The plastic trim around the sterio on the dash / window swiches is different to some PH1's aswell, I think, and the seat are half leather.
There is not a huge amount different to a 1.6 16v really, they are nice cars and you don't see many RSi's about.
They go well and feel pretty solid on the road (like a bigger car), I think your valver would be quicker but that being said the rsi is not a slouch.
My rsi is only 300cc more than my gf's car but you can feel a difference in power, especially on hills where the RSi is great. It's the only hatch that I've had that will go as quick up hills as down them.
In terms of handeling, it will probably feel more soft around the edges than your valver.
Mine is so quiet you can't even hear it tick over. If you do alot of motorway miles it'll be relaxing to drive, it will do 40-50mpg all day.