It's just really awkward.  Especially when I want to cancel the action.
Ctrl+Esc really doesn't work that well.  You just end up popping up the
start menu.  Funnily enough I did implement a very similar system in one of
my applications a couple of years ago and then took it straight back out
again because of the Ctrl+Esc issue.

Also when I'm working/debugging I might not always catch the name of the
file I was looking at, (there's a good chance it wasn't my code to begin
with) I just want to tab-through until I see the code I was looking at
before.

(I also liked being able to keep my finger on ctrl and do 'C', 'Tab', 'V' to
copy a line to another file.)

But yeah, thanks for the info.  I'm now back in Ctrl-Tab heaven.  ;)

(For anyone else looking for this you have to reassign (shift+)ctrl+tab back
to
Window.(Previous/Next)DocumentWindow.)

James