Try scrolling large amounts of text in MacVim, where the whole screen is refreshed, and then try the same in xterm+vim. MacVim is painfull to watch doing this, feel like working over a 300 baud modem. xterm/X11+vim are VERY fast combination for pure text editing, and that matters to me greatly. Same applies to Terminal.app (and it refuses to work in 256 colors, unlike xterm)