The results for localized stuff, e.g. a local store, are horrible. The results for complicated questions where the query is either not very specific or the page might not have all words, are also really bad. But if you have a good idea of what you're looking for, which is most of the time for me, it works very well.
At least it's honest about not having results whereas Google presents 5 billion, all of which are missing one of the three keywords (which it notes in a small, light grey text, which you only notice after the first three results were completely unrelated and you were wondering what went wrong).
For example, "new double c++" is the query I did most recently and in the top 3 there are 2 results that answer my question.
Making something up at random like "torrent clients" gives me as top hit the Wikipedia article "comparison of bittorrent clients", which is better than expected.
I can't seem to think of a vague query right now. "audio books" gives me sites with audio books; "psychology books" gives me articles of 'the best 50 psychology books' and such; and looking in my query history, "draw unicode" seems vague but the top hit (shapecatcher.com) is the one I was looking for.
Something localized then: "drankwinkel echt" (where Echt is a place and drankwinkel a liquor store) indeed gives terrible results. The store name, surprisingly, works though: "gal & gal echt" gives similar results to google.nl.