xp 900 VS 800 turbo

I have a 2010 RZr S with the MCX Stage 1 turbo, FST Long travel w/ dual rate king shocks. I want/ I NEED more power. The question is do I do motor work and keep the machine I have or start over with an xp 900. I have the opportunity to trade my machine for a stock 900.

Help I am not sure which route to go

any advice and opinions welcome
Thanks