The problems I've had with SO is I get far less response to the tough questions I've had, which I think is only 2 so far.

Answering questions is also difficult unless you live there. Most are not worth answering anyway (e.g., very low quality or duplicates), but there are clearly several key experts that do seem to live there that do get them "answered" within minutes, often in the comments since again the "question" doesn't merit an official answer.

I always have VBF and SO tabs open during the day while at work, but I rarely check SO anymore unless I'm looking for an answer since its search is superior to VBF's unless I do it via google perhaps.