I often ddg problems related to Ubuntu. I had many encounters where someone had the same problem than me on askubuntu, but the answers where unhelpful, sometimes only the question was posted with no answer at all. Or the original poster stated he solved his problem, without posting the solution. In most cases, on SO I found relief.

Then there's also the conceit that SO has hit upon a definition of what a good technical question is (or, more specifically, what isn't a valuable technical question), and they stick to it despite any evidence to the contrary. I've seen questions that fail their over-restrictive criteria that have far better answers than many that do.