I go back a long way with Handspring. I started with the Visor Prism. My first impression of the Treo 600 is that it is a big step forward. Yes, it would be nice to have the better resolution screen. Yes, the speakerphone is better, but is still lacking (echo problems, tinny sound). But.............

1) form factor is excellent,
2) screen is much better in sunlight,
3) camera is adequate for fun shots,
4) five way navigation is intuitive,
5) reception is slightly better than with the Treo 300,
6) the Sprint bump enhances my hearing,
7) Treo 600 is solidly built,
8) processor/syncing is fast,
9) Blazer is much faster, and
10 You got to love the SD slot.

Would I pay $600 for the phone? No. But $399 (Treo 300 upgrade price) for the Treo 600 is a good value.