I did, the major reason when that I switched back was due to UTF-8 problems, and as far as I know the line editor is still blissfully unaware of multibyte characters.
There was also trivial stuff like coloring the prompt, which for me makes things easier to find on a terminal full of text and additionally highlight that you're root (in addition to the #-sign).
In all fairness, coloring (and probably everything else I was annoyed at) is doable and wouldn't have stopped me from trying it out a bit longer though.
"Home life as we understand it is no more natural to us than a cage is to a cockatoo." -- George Bernard Shaw