If you accidentally pipe hundreds of thousands of lines of text (e.g. from find) to stdout, you will feel the difference. Some terminals (e.g. xterm) are particularly slow and will stall until it is done processing all the output. urxvt is not the worst, but could be better, yet doesn't always achieve 60 Hz.

My gripe with (u)rxvt (last I checked) is the atrocious font rendering and character spacing if you chose a full unicode/nerd font.