[JERSEYDEVIL]

to answer ive test drove nine different xrx300's after assembly, the best top speed i have gotten on the same strip of road was 54mph (according to the stock speedo). the others were all somewhere between 51-53 consistently.
as far as torque there is a very noticeable difference between matting a 300 verses a 150. it doesnt throw you back in the seat and make your eyeballs roll back but it does launch significantly stronger and you know you are not in 150 land anymore. as far as the dunes, not sure, never been there and i am not much of a sand rider although florida has a ton of sugar sand that has never been a huge issue. if you think the 150 "might" make it than the 300 "should".
i have already received an email from my trailmaster guy that the 1st batch was sold before they made it to the warehouse. the next batch is due in mid july. he encourages me to let customers know if they are interested to pre order it now so if there is an interested member let me know.