I have essentially the same browser on a palm lifedrive, and it's
not awful, but it is somewhat limited. I've used it to view content on this site and engadget, but it's essentially useless for online banking. etc.... It also has trouble saving links to the the hard drive if the page being viewed is too large, or if it's just feeling finicky.
The palm wifi stack is also kind of unstable, so device resets are common, i.e. about 1 per day, if you power off or switch from the browser to/from other apps.

I also tried an HP IPAQ 4700 with a VGA screen for a couple of weeks. Pocket Internet Explorer, or PIE, was a pretty miserable browser, but there are plugins available that make it much nicer, e.g. for tabbed browsing. The problem is that the cost of the device and the add-in modules for PIE, along with an upgraded PDF viewer, since the bundled one couldn't read most of my documents, was WAY too high for a PDA. Perhaps things have improved somewhat with the introduction of win mobile 2005.

I don't dislike my palm lifedrive at all, but I think the 770 will be much, much better.