Come on, DDG is not storing datas, neither do we. This was a good feedback and we're looking for more?
Beside you know how hard it is to get just a fraction of attention from the community unless you game the stats...
Thanks for downvote :-S
But if you want my feedback, have it: for your "don't track" claim, I could trust you (after all, I have to trust someone in the end), but just loading the homepage send my data to Youtube (video) and Mixpanel (analytic).
Even your advertised feature, "preview the site before you browse it" is not exactly privacy-friendly. It just load the page in an iframe (if you guys want to do it right, see the ixquick-proxy on startpage and ixquick).
Also about the design, I don't think everything should be flat, but I just can't bring myself to like it. It feels like a '90s site.
Sorry for being harsh, but you pretty much asked for it.