Is it possible to get code completion for R in Emacs ESS similar to what is available in Rstudio?

Question

Rstudio has a great code completion feature. It provides a quick view of functions that start with a given string, as well as function and parameter definitions.

ESS

Answer 1

Or maybe we should all use search:

Emacs autocomplete-mode extension for ESS and R

I don't want to be grumpy, I found this few hours ago and I'm still shocked. It works like a charm. Though I still prefer the old-style pop-ups. =)