For me the text is bad either way. But gaming and movies are much better.
The pixels and pixel pitch is greater on TVs but that is part of the cost advantage since you're supposed to be further away. The downside is that any font below 14pt is terrible to read from more than 2ft away.
With browsers and the desktop and many application view options you can resize the font.
Still, the picture is more grainy on my 720p; it has a VGA connector and the picture was not grainy and pixels blended together much better. However, movies and games were not more grainy that the desktop. I assume it is the scaling and color correction of games' and movies ' rasterizers.
So all in all, if you are not using the computer as a media player and you find a monitor of the same size and price, you should get the monitor; but I don't follow newer LCD monitors. I chose an HDTV over a monitor because I didn't think there were any 26" + monitors with glass instead of a matte screen.