I have the RXT-X and it is larger than the RXP as mentioned above. I personally would not go with the shorter ski as it is a harsher ride and you can't have three people on it. Which means you really can't tow anyone in most states as you need a driver, a spotter and the person you are towing. Since the ski is rated for two, you can't tow as all passengers must be able to fit ion the ski.
Nothing wrong with the RXP, just not enough ski for me in regards to physical size. Nice power plant though.