Used Ion for years but finally just "upgraded" to fvwm2 and multiple tmux terminal windows. Reason? More often than not dozens of Unix hosts are being accessed through SSH rather than X. Tmux is always there, regardless of method of connection. Also, use the antique "nvi" (rather than Vim or Neovim) whenever possible. Same reason; it's always there, no tweaking.

If I find myself craving extra functionality I'm probably overthinking things and am in need of a vacation.