I have the whole set-up and only recently changed my whole computer system to Windows 7. I'm not sure if it will install on the upgrade or not. If it doesn't, I will reinvest for sure. I don't do just paper piecing, but when I have, it is absolutely wonderful for scaling stuff up/down to the size I want and then simply printing out.
In short: I love it.
An aside: I had EQ when it was version 5 and sold it for about a third of what I paid because---even though I'm fairly computer savvy---I discovered the learning curve was far too great. I'd rather be sewing. I do remember in one of the EQ blogs that the question came up and many admitted they really like just playing with the blocks, designs, colors, etc. on the computer and do that far more than actual quilting. EQ just wasn't for me but Quilt Pro definitely was/is.
Hope that helps.