After much thought I've decided how I want to differentiate the free and professional versions of Data Comparisons. Essentially, all the work I've put into Data Comparisons thus far is now in the free version: Data Comparisons Express. That includes support for all versions of Microsoft SQL Server. That means I'm giving away a lot for free, but I'm OK with that. I've submitted the software to a couple of download sites so the upcoming weeks should be interesting.
In many ways the Express version is also serving as a pilot program to test the waters and see what people have to say about it. And then I'll take the feedback I get and perfect it the best I can from there. The professional version is still in the works, but it will have all the same features plus a few more things to make it more powerful. Some of the immediate features I'm planning are in-place editing, multiple table comparisons, and the ability to save comparisons settings to be reused. I know that even this feature set doesn't compete with some of the top dogs but I'll be pricing it accordingly.