I have heard that most die-hard Sea Doo riders that like to mod their machines do disable the OPAS as it does interfere with handling at higher speeds especially when in rough water and the boat is coming out of the water frequently. I am told it can get rather unpredictable as to which way it will want to go on landings and gives it a rather unnatural feel compared to other pwc. I booked my new RXT today so I guess I will know for myself next week.
For information on Sea Doo perfomance work and tuning you can check out
www.rivayamaha.com, they have a great performance forum. Also
www.greenhulk.net. He is the authority on these.