The Audio Visual Controller (AVC) is only capable of 1920x1080i. The display itself is capable of 1920x1080p if you connect a device directly to the DVI port on the display instead of the DVI port on the AVC. To make this practical most folks are using Gefen DVI switcher. To date, folks have gotten iScan, lumagen, mac, nvidia, and some ati models to work this way at 1080p. It is not an officially supported resolution, but many have gotten it to work. The GX is the only model with external AVC, thus is the only model where you can bypass the AVC and go direct to monitor. AVC still needs to be connected even when using as computer monitor.
Clayface is a defect in some of the displays which Sharp has said they have fixed in a new firmware release that is being tested now. It doesn't affect all displays and is by no means indiginous to the display.
The display is one of the best for LCD, but in the end it is still LCD. There are good points and bad points, too many to discuss here. I think the black levels are acceptable, but I also think the black levels on Pioneer are acceptable, where some do not. If you are in the "must have Panny plasma black-level camp" then LCD is not for you. I have seen LCDs where I thought the black levels were not acceptable, and the Sharp is way better than those. Overall I've been pretty pleased with the display and the SD picture quality was much better than I expected. The Sharps are loaded with features and surprisingly I'm using most of them.
There are some minor issues I've noticed like the HDMI port forgets which stretch mode I had it configured on and the audio sometimes clicks or pops if the Dolby Digital stream is very corrupted (using internal QAM or ATSC tuner) I consider the latter an exception as normally my digital HD signals are clean, but I'm currently having problems with Comcast. All receivers will click to some extent when the DD stream is lost but most will try to mute the sound instead of popping.
If you need a media cable longer than the one provided, they are a little pricey, but not more so than AVC media cables from Pioneer.
There are fans on the unit so you can't mount flat on the wall as you need some clearance for airflow. The fans are one of the quietest I've heard so that's not a big issue.
The HDMI port worked well with Panasonic S77 upconverting HDMI player.
The stretch modes are available for 720p/1080i using internal QAM tuner, but for DVI/HDMI the stretch modes are only available for 1080i, not 720p (which is limited to 16:9 standard)
There are tons of inputs on this thing, 2xcomponent, dvi (dvi-d, dvi-a, dvi-i), hdmi, svideo, firewire, pcmcia, 2 ntsc tuners, atsc/qam/cablecard tuner, and twin (side-by-side) picture.
There is a builtin 1-bit "digital amp" ala Panasonic digital amps in the TV which works well with DD streams.
That's about all I can think of for now.