I map held Caps to Super (so I can switch windows and use other higher-than-application-level shortcuts without leaving the home row in dwm), but yes, definitely don't limit yourself to one use for your keyboard's most convenient key without a use. In X11 it's as easy as
I really don't like chord like shortcuts, while ctrl and [ are positioned in a way you don't have to contort your hand it kind of requires you to move away from the hjkl row or stretch your pinkies. Consider mapping esc to jk (as a sequence) it works surprisingly well.
inoremap jk <esc>
and
inoremap <esc> <nop>
so that you never use esc again
not having chord like shortcuts was one of the main reasons that led me to try vim over emacs in the beginning, so I kind of think they're "anti" vim.
Having ctrl-[ in your muscle memory has the advantage that it also works in other readline programs that have a vi like interfacee, e.g. bash, zsh and many db consoles.
This is now my muscle memory escape key since an embarrassingly cheap Bluetooth keyboard of mine only allowed escape == home button on my Android devices.
Pro Tip: Park the flesh of your left palm near the left ctrl key and use that instead of your pinky for ctrl. I admit this feels a bit weird at first but avoids the need to lift your fingers from the home row. Super bonus: use ^H for backspace. Try it out!
my reasoning was : you could have mapped caps lock to ESC but you did not. So maybe you are using CTRL too much (CTRL-V maybe?) which is not the best way to use vim.
No your reasoning is way off. I map to ctrl rather than escape because I want to make use of the Insert and Ex mode ctrl shortcuts.
For example, if I want to insert a register into the ex mode command line I use ctr-r <register>.
Or if I want to pop out of insert mode for a single command I use ctr-o.
E.g. inserting opening and closing tags when a suitable plugin isn't present. Insert the opening and closing tag, jump back to command mode with ctrl-o, move backwards and you're ready to insert more text.
Can't speak for everyone, but I use this[1] keyboard most of the time, and it doesn't have a Caps Lock key to remap, but instead has Control where Caps Lock normally is. So using ctrl-[ is much easier than reaching up to the escape key.
Using Ctrl-[ is perfectly fine if that's convenient to you. Some people doe "inoremap jj <esc>" and double tap j to exit insert mode. If it's faster for you than pressing regular escape, it's an improvement, and thus good.
Politely, I'd consider rephrasing this in the future. Not everyone springs forth into the world with a 5kloc .vimrc. Everyone is incrementally learning from someone else at their own pace.
