From: Michigan, U.T.B.
Absolutely. LCD's only look good at their full resolution.
When the 800x600 resolution is "stretched" to fill the full screen on an LCD, the pixels have to be "interpolated" to the closest approximation of the actual image, so it's a garbled image.
On the CRT, the size of the monitor's pixels actually changes to keep a 1 pixel to 1 pixel relationship for a true 800x600 image, just with larger pixels than what you would have with the monitor set to 1280x1024 for instance.
Plug one of your old CRT's in and see if it works better.