Because this question is important and you are spending your hard earned dollars, I am going to address the question here. From my personal experience, I have never been sorry that I have purchased an upgrade. Upgrades always include some of what the current users have been begging for over the duration of the last release. Upgrades often, not always, fix clunky poorly designed features that users complained about in the last release. Upgrades usually capitalize on new technology like new operating systems, both Quilt-Pro and EQ are maximizing on Windows 95 technology this time around.
Upgrades utilize the faster processing capabilities of newer computers.
This allows for more complicated enhancements done in less time. It means that more and more of your creative work can be completed in your quilting program. Many of the enhancements that are being added to the quilting programs are similar to the ones found the graphic programs but with a quilter overlay. Bottom line, you simply have not had time or the right motivator. When the right motivator comes along and you take the time to learn the program, you will begin to search out others doing the same thing and you will find very few fellow quilters using or supporting the older versions with books, Internet mail lists and website information.