Two main reasons. The compressed audio is really very good. I like the compressed 24. Only about 20% as large as a PCM 8 file and still better quality.

Two: The user interface with the navigation pad is very nice. It takes a few minutes to figure it out, but you can do everything with a single button press.
After the first day, I could record without even looking at the Treo.

Other issues: Records equally well to either Internal or SD memory. Includes a conduit. Is solid. Good tech support. Many features.

Seems like a good choice to me.