I have a C750 - before had a 5000D, and definitely the C750 screen is much brighter and sharper than the 5xxx screen.
I have seen the 6000 too, and that screen is even better than my c750 - its bright and crisp and plus is you can read the screen in bright daylight too.
And of course as for resolution, the 7xxx and 6000 screens beats the ipaq\'s out of the water. I havent even booted up my 5000D for quite some time as I just cant look at that older resolution anymore.
As for the Toshiba e805, it must be the same since they use the screen from Sharp. The downlside of course is that not all apps run in VGA mode on the Toshiba without the hack. The 6000 on the otherhjad works standard VGA for nearly all apps - its actually not the VGA limitation, but the design of older apps meant for the 5xxx series and secondly, it has on-the-fly rotation.