Yes, the lack of a built-in flash is annoying for me as well. I usually do not use it much, but there are cases when it is indeed nice to have.

I wouldn't really mind a FF sensor, though. In the future, should FF sensors become available to cameras of the 7D/50D/40D... segment, I'd consider it. While I have no direct experience of it, FF are supposed to also produce much less noise, all other factors held constant, for "obvious" physical reasons.