This works great if you have all the commands memorized. If you don't, fuzzy matching in ido is a fantastic way to find commands and variables that do what you want (Emacs has a great tendency to name user-facing commands very sensibly a lot of the time). Most of the time I can use C-h f and C-h v to figure out how to configure something without having to read the documentation.

In addition, ido and flx-ido provide more efficient and faster (you don't have to manually invoke it) autocompletion than what you can get with prefix-based tab completion.

Also, I haven't had any issue with ido+TRAMP - everything works seamlessly on my end.