Hi Scott,
I am in the middle of doing what you are planning to do. My advice to you, is that if you don't need to migrate the application, Don't do it.
VFP6.0 is a great product, and it converts 3.0 projects to 6.0 format very easily, but I've found that the exact same application runs quite a bit slower compiled under 6.0 than it does compiled under 3.0.
In order to make the application get the same response time in 6.0, I've had to upgrade from Pentium 200 MMX to Pentium II 233.
If you do need to convert, be aware, that you may run into the same problems. From what I've seen and heard, this is related more to applications that typically have a lot of user interaction, and data lookup functionality.
Hope this is of some help. I'll let you know if I encounter anything else in the next few days.

Rob