IMO, plan mode is pretty useless. For bug fixes and small improvements, I already know where to edit (and can do it quickly with vim-fu).

For new features, I spend a bit of time thinking, and I can usually break it down in smaller tasks that are easy to code and verify. No need to wrangle with Plan mode and a big markdown file.

I can usually get things one-shotted by that point if I bother with the agent.