Thanks to Stampin' Up's free 30-day trial of My Digital Studio Express, I took the plunge today and downloaded it! MDS Express has pretty basic content: one set of DSP, one stamp set, lots of cardstock and ribbon colors, lots of punches. The great thing about that is that you can just purchase the additional items that you want as needed. Or if you like the idea of having lots of stuff at once (yes, that's me!), you can purchase the full My Digital Express CD.
If you've done any kind of work on computers where you deal with images, MDS will be a snap. I found the program easy to use without having to access the help feature. What I loved: I could resize any photo or mat. I could drag everything to where I wanted it to go. I could also resize the punches and stamps; if only that worked in real life!