OK, going to wade in here with my take on owning a sl5600 (which I bought about a month before Amazon dropped the price from USD 500 to USD 300). Bah.
Physical attributes aside, my main hassle has been software based. On the Sharp ROM, the calendar, to-do list, and Notes all sync with my PC after a fashion. Its not as good as my old Palm, but its bearable. This was one of my requirements.
The other thing I wanted to do with it was to use it as a network troubleshooting device. To that end I\'ve been able to get Kismet and nmap to run on it. However I haven\'t been able to get Wellenreiter, a decent notes application, the screen rotation applet, ethereal, or airsnort to run on it. Probably some others as well. These have all been adapted to run on the 5500, and will run on the 5600 if I change to OpenZaurus ROM. However if I change to the OZ rom, it is currently too unstable to use (took me 6 hours of conf file hacking to get my wireless card to half work for eg.) and I have to forgo the PC synchronization.
In short, the software just isn\'t there for the 5600 at the moment, I\'m sad to say.