XP to Win7 is well worth it IMHO,Vista SP2 to Win7 hmm not a big jump however its optimized better for low spec hardware and has a few new features.
I've two Vista SP2 PCs and Win7 RC PC,personally I'm doing a full hardware upgrade in Oct/Nov since my 3800+ x2 CPU/motherboard/ram etc... is getting a bit long in the tooth,I'm going to replace my OEM Vista with OEM Win7 version ,my other PC I'll stay Vista SP2.
I think some of the hype is from XP to Win7 users that have stayed away from Vista,I think Win7 is a bit hyped(nothing wrong with the OS however).
I did not notice any real difference unless you run it on low end hardware(1GB ram etc),anyway Vista SP2 or Win7 are both very good operating systems IMHO so can't go wrong with either to be honest.
I guess you could say I'll be sticking with both Vista and Win7 until Win8 arrives

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