If you want one, check your local Dick's/Golf Galaxy/Golfsmith/etc. They're $149 brand new everywhere now, plus most places have a lot of these used with different shafts. You might find the exact club you're considering and be able to demo it before buying.
As far as a comparison, the 580 XD followed the 540 time wise, and was the last offering prior to the r7's coming out. I'd say you're not going to notice a significant difference in the 580 and the 2 you already have.
With all that said, the 580 XD is an outstanding driver and you will like it if you decide to buy one.
I had one as a backup to my Ping G5 until my wife hit it once...haven't seen it since!
As far as a comparison, the 580 XD followed the 540 time wise, and was the last offering prior to the r7's coming out. I'd say you're not going to notice a significant difference in the 580 and the 2 you already have.
With all that said, the 580 XD is an outstanding driver and you will like it if you decide to buy one.
I had one as a backup to my Ping G5 until my wife hit it once...haven't seen it since!