Thats awsome mtbbiker, I remember when you were searching a few months ago and you were looking hard at the FXR. The 575 is one of the bikes I recommended to you and still would have no problems recommending the 575 to anyone even if they had no spending limits.
I have a 575 and a 5 Spot now, though I dont have a lot of time on either I really like both frames alot. I rode the 575 at Mammoth Mtn about 6 weeks ago with my wife, mostly road some of the easier trails like Downtown and Beachcruser, but I still hit as many bumps and rough stuff as I could find. Including going as fast as I could go in certain area's. At the time it was set up like a trailbike weighing 30lbs, Z1FR fork and 750g tires. The bike really rocked! I didnt have any tire slippage, which is amazing at Mammoth, the wheels tracked as well as any bike I have ridden, the rear end was so plush I couldnt believe its an air shock. I hit as many bumps, ruts and rocks as I could find just to test the rear end, I know that I used all the travel but never felt any hard bottom outs.
This last week I rode again at Mammoth this time on a new heavy duty built 5 Spot with a bunch of yahoo's on FR bikes. I rode trails like Skid Marks, Bullit, Velosity among others. Man, I sure was beat, those trails are tuff. I was under biked but the Spot heald up. Its kinda hard to compare because of the different trails and speeds I rode at. The bike feels like it is more than 5", its plush alright, and pedals well, but, the 575 is as good a trailbike as the 5 Spot, I know Im going to get slammed for that one.
There's a post here on the Yeti forum about a ASX I believe and I asked a question about the 575 and several replies came back regarding the 575, you should defenetly read them.