I think what he means is that first for a website some r made for a specific res and when ur res is larger than that u get a border with nothing on it, which can detract from how good the website looks. As for games, too high a res makes text and other things harder to see. As for running at reccomended res, it can be interpreted as 2 fold- for CRT's running at the reccomended res yields a good refresh rate (res higher than that u may see flicker) and u also prolong the life of the tube by running it at what it's meant to do. As for LCD, anything less than the number of pixels on screen looks bad unless it scales to an integer value, like 1280x960 -> 640x480.
Tears, I'd say go with a 19" CRT if you have the desk space and run it at 1280x1024 (easy on the eyes, and a good crt will have a refresh rate of 85hz or higher at that res- check outthe P95F+ for some very high refresh rates). True you'll get less FPS when playing games, but new vids cards should be able to handle new games and those to come in the next half year well at that resolution. The effect of games looking bad w/ a larger monitor may also be what he means as you'll want to turn the resolution higher so that there are less ridgies and image overall looks better, and then it may become choppy.
Also please disregard the post from Williamette_Sucks, this forum welcomes you and will gladly answer your questions.
Hilbert space is a big place.