It seems to only be UI improvements - the search itself is still terrible. I have DDG as my primary search engine, and I would say I have to repeat 50% of the queries in google, which has actual useful results after the first half page of ads.
In the past year or so I feel like I've had to resort to bangs like !g more and more. It's like Boolean searches don't work with DDG anymore. Quotation marks in particular seem meaningless to it.