There\'s a enormous pit between Psion S5mx Device and a Zaurus: the software.
Zaurus hardware is exactly what all Psion users were asking for: 65535 colors on a 640*480 screen (instead of 640*240 16 gray scale), imaginative design (keyboard and swiveling screen), powerfull processor (400Mhz PXA255 on a 200Mhz bus instead of 27Mhz on a ARM7110), lot of memory (64Mo SDRAM instead of 16Mo of conventionnal RAM), big internal flash (128Mo of r/w flash instead of 16Mo of ROM on 5mx), CF and SD/MMC card support (full card compatibility instead of only memory CF on S5mx), usb/serial/irDa support (only serial and irDa on S5mx), Wifi/Bluetooth card... drivers (none on 5mx), Multi-media player, Sync with Mac, very tinny...
But the internal software can\'t be compared. In fact yes, the comparision can be made but you should inverse the device. To be short: Zaurus software are crap and unusable for most Psion users. The Psion 5mx application are still the best despite all this time. With its 16Mo RAM, 16Mo ROM and its old ARM7110 27Mhz processor, a Psion S5mx is more complete and faster than a Zaurus SL-C860 400Mhz 64Mo RAM 128Mo ROM and with an ATI accelerated video card. The 5mx with its 8 years old is a dinosaur. It\'s the 5mx that should have been called Zaurus and not the Sharp device. The Sharp hardware is very good. The Sharp software deserve the Zaurus name.
Note : Zaurus PDA QT/E libraries are 100 time easier and complete than Psion Epoc ones. In spite of everything, the software are worst. They are million of users on the market that are still waiting to be able to replace their old Psion by something. As padishah_emperor said in another thread, it\'s not the Sharp plan.
GoLinux, if you want to play with Linux a bit, flash and reflash a device every month, play with X11 or Qtopia on an ARM device, then Go Linux and Sharp PDA. If you want PIM and you are not a developer then... wait. Wait because Palm or Pocket PC are not better and because with some luck, Sharp will sell a SL-C8000 with 860 shape but with bluetooth and wifi inbuilt (and improved software? :cry: ).
Note : With pdaXrom you can run powerful applications like nedit, AbiWord 2.0 or Mozilla Firefox. Opening them is like opening a Qtopia applications but pdaXrom apps are more powerful. If you have already tested a Psion Series 5 (not 5mx), the software speed and screen updates are equivalent. (S5 is approximatively 1.5 time slower than a S5mx).