DPI is irrelevant, the N800 is 800x480 the C1000 is 640x480 - it's all about how many pixels you can see and here the Sharp falls short. I've used 640x480 screens to surf, they're horrible because most web sites have to be reformatted whereas they do not at 800x480. You bet thos extra 160 pixels make a difference!

The 6GB HDD will most certainly be handy, but will also suck down your battery faster than any 2x4GB SD or even 2x8GB SDHC cards will.

CPU - there's probably not a lot in it, but the Intel chip (ARM9?) is probably less powerful than the ARM11 in the N800, even if it is clocked faster. That said, much of the hardware in the N800 CPU is currently ignored by Nokia.

The other points I'll concede - they'd be nice to have on an N800, but I can live with them (although I'll need to get myself a case...). You can charge by USB - use the Nokia USB charger (announced recently - check the ITT News page)

Still, with the Zaurus line being terminated I'd question how long Sharp will continue providing OS updates. Not sure I'd purchase a device *after* it has been EOL'd, unless you could find it heavily marked down in a sale.