The reasons I run gvim rather than terminal vim are basically all because sufficiently capable terminals do not exist:

- The excellent "solarized" colour scheme only works properly with 24-bit color unless you're willing to mess with the terminal palette and break all your other terminal apps. No terminal I know of supports 24-bit color.

- I have a handy keybinding that cycles through open windows and tabs, I find it makes the most sense bound to Ctrl-Tab and Ctrl-Shift-Tab. Neither key can be bound in any terminal I know of.