Well give me your opinions. 04XT vs 04 XTR Crank sets.

From what I can tell the XT is the same as the XTR except for Aluminum alloy and 63grams. Can anyone feel the difference between these two cranks.

I ordered the XT from cambriabike.com. Great place. The cost difference was only $180. But before I put them on I would like to hear from you guys. I put my money into the Mavic Crossmax SL Disk wheel set and a Nokian NBX Tubless tires. However I can afford the XTR. But if no dif, then why. Most seem to go with the XT brackets. My stuff will be here on Monday. Just curious.