450R huh? I almost bought a new 450R last year, but when I went to do the deal the salesman told me that the unit they had available just sold. I ended up going with the 700R. The reverse has come in handy more than once on the trails.
I also test drove a 2007 Polaris 525 IRS. A friend of mine is a Polaris dealer in Georgetown, TX and he let me take the demo out. I am not a huge Polaris fan, but it was a nice quad. I love to slide through corners and I hear the IRS makes this more difficult. I do not know since I have only had very limited seat time on an IRS machine, but that's what I read.
I watched some video on YouTube of the 700XX in the dunes. Looks like a nice quad. I will have to ride one before I will know if its something for me or not.
I will for sure take a camera and get some still shots and some video. We have a new helmet cam that we are going to try out as well. I will post some pics up in a couple of weeks. My Father-in-law bought his nephew that lives in Wisconsin an 07 Polaris 525 IRS last summer. The sh*t talking has been going on from that end for months. They think the 525 is going to run off and leave my Raptor. Stock vs. stock they are very close according to the shootouts. They say the Raptor is a bit faster than the Polaris 525, but a little slower than KTM's 525. Being that his is stock and mine isn't, it shouldn't be very close.

I don't think they know that mine is modded, but they soon will.
Take Care.
John.