I suspect his problem is more with Windows and its brain-dead font rendering. Vertical strokes are the ideal case for subpixel anti-aliasing on a typical LCD: you get 3x the horizontal resolution. On a typical 100dpi screen this gives you 300dpi horizontal resolution, which is around the low-end for print quality. On modern 200dpi "retina" displays, you get 600dpi horizontal resolution which is more than enough to make Computer Modern look good. But ClearType has a strong preference for aligning positions and sizes to whole pixels, giving you horrendous kerning and sudden large jumps in font size and apparent weight as you increase the requested font size.
I'm using a Retina MacBook. The readability problem with Computer Modern is intrinsic to its design, and even a 200 dpi screen just isn't enough to make it look good (IMHO). But it's definitely much worse still on Windows.
My question is: why use this particular 1980s font developed to showcase a dead-end stroke rendering technology, when there are much better alternatives around?
Why use it? It's the default, and otherwise you have to find a math font and text font that go together all on your own. At least that's why I use it: laziness.
I agree at 200dpi is not quite enough for Computer Modern. But I claim that, say, 7200dpi is far more than enough, and then it looks great.
