Our downtown mall has a Dell outlet kiosk and I found myself admiring the gorgeous screen on the X50v. Built in wi-fi and blue tooth would be nice, and the ability to put the screen in landscape mode for typing etc. Those aren't bad reasons to go for the x50, but for the time being the X5 does pretty much everything I want it to. I play movies, surf the net via wi fi, take notes at meetings, keep my calendar. It also has better battery life.
Two things that would matter to me video/vga out, the ability to work with a wireless keyboard/mouse from a regular computer, and even better battery life, and maybe a better web browser, and a better quality mic for doing voice notes or recording lectures. The Axim 5 was a huge jump from my Casio in most every way. The jump from x5 to x50v is more incremental.
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