For very technical queries I somehow already know that google gives me better results at the top. DDG results feel more like a dice roll.
Two things I also miss are "site:url" filters (dont know if ddg provides this) and date ranges, for example results within the last 3 years.
Well, maybe it's possible but I have other things to do than to browse around ddg or learn a bunch of bangs. In my opinion this is the main barrier to entry. Provide me all the possibilities on a single screen or behind a menu and don't expect user to dig around the docs. There's a lot of potential which will never be uncovered by alot of users, so they stick to google.
How can you miss it when you haven't tried it?
Yes, ddg supports it 
It also supports limited date ranges, like last week, last month etc 
site: doesn't work in my browser url bar at the start so I got used to prepend !g... I know, a terrible workaround..
Could not find a way to search within specific years which is very useful for overloaded terms. It says, they are working on it..