Quote from the review at The Gadgeteer:
I must admit, spending $499 on something the size of a wallet is a little daunting. PDA’s are the sort of thing for me that I’m always trying to find a use for. In this case, I determined beforehand what I wanted to do with a new device, and set out trying to find the one that was closest to what I had in mind. Fortunately for me, HP decided to release the 4355 just before I went shopping. In the end, I honestly think I couldn’t have made a better decision. I can use the 4355 anywhere I go, and it provides me with a very desktop-like experience.