As one guy around here mentioned before, it would be nice to get a brand new Z with all the modern and quite useful things - 624 MHz PXA270 CPU, 2700G video accelerator and 128 Mbytes of RAM as well as NAND. Most of those features are already present in high-end Windows mobile handhelds, like Dell Axim X50v. I'm unable to understand why Sharp doesn't want to put them all into new Zaurii. To my mind, I need only few things that my C760 doesn't do too fast: 1) Smooth midi playback via Timidity; 2) Smooth DivX playback of CD titles without having to recompress them; 3) Swift WWW surfing via Firefox; 4) Performance of slow 386 ar at least 286 when playing PC games via DOSbox (with SB sound, of course).
I'd like to buy 3100, if I wasn't afraid of some things: 1) Limited performance of 416 MHz PXA270, especially when executing video output; 2) Extended size and weight of 3k series; 3) Very unserious and inconvenient 5-way joystick instead of good ol' T-reversed cursor keys (I've got really used to it ).
RAM limitation, of course, stays here as well. And programs like multiple-windowed Firefox are still crashing at 64 Mb space...