There's quite a big difference, as the 700wx runs Windows Mobile and the 755p runs Palm OS. I'm personally a fan of Palm OS, but your opinion might vary. Also, the form factor is a bit different, as the 755p does not have an external antenna while the 700wx does (I personally like the antenna, but some people don't). If I were you, I'd go down to your carrier's store and try out each device for a little bit. Palm OS is much easier to use, while WM has some interesting things such as multitasking (which can be a good thing or a bad thing).