But I'll keep an eye out and actually write down particular queries where I see these phenomena, and send them along.
I agree with your chagrin at the loss of the plus symbol.
I do the same search on Google and it gives me links to Currys, Tesco, Argos and Maplin (all UK shops/sites). And it links me to Amazon.CO.UK and Ebay.CO.UK.
I don't use DuckDuckGo for searching for products which I want to buy, because this is always what happens.
I suspect DuckDuckGo is a much better search experience for people inside the US than outside.
EDIT: Ooh. I've just noticed that if I set my region to "UK" in DuckDuckGo the results suddenly become far more relevant. Why isn't this set by default? Not only am I coming from a UK IP address, but my browser is sending "Accept-Language: en-gb"
As far as I can tell, Google will always tell you when it thinks you made a mistake, and provide a link to search for your exact query.
Lack of date-bounded search is a frequent reason to resort to Google. Special collections (Scholar, Books, News) others.
I'm actually relying far more on DDG image search than even a few months ago -- the results are getting good. Also the instant answers, which are getting good.
There have been a few times in recent past where DDG searches have turned up empty (or unsatisfactory results) while Google's nailed it. Actually went hunting for an example and got lost which is why this comment is so late. Couldn't find the example though I'll try to remember to submit it when I do.