Emacs is too broad, scattered out thin, horizontally-oriented and lispy for me to be usable. It reminds me of a GTA-like sandbox game. There's a sandbox and then there are lisp scripts in it lying flatly. This is very different from Qt Creator -- the latter in much more vertical in its design, and it shows.
Anyway, it's still a matter of preferences. One should check out both, of course -- it's just that one would presume 'emacs' was tried (even at least once) by everybody here among LWN crowd already.