Though it lost out in a number of the tests, when you look at the actual differences, it's actually quite impressive considering it's only a beta and not finished.
I'll be moving to Vista 64 myself soon - had a copy of Vista Ultimate for a while now but never got around to using it. I have to now however as I need a 64 OS due to the amount of RAM involved in the new PC, Core i7 CPU's (a 920 in this case) need it fitted in sets of 3 rather than pairs.