Yes, I've been switching back and forth from DuckDuckGo and Google many times over the past three years. At the beginning I liked some of the features that DuckDuckGo had (bangs, disambiguation) but Google would always win on overall web coverage and speed. Lately, I find myself using DuckDuckGo for longer and longer periods of time before stumbling on a query that gives me a better answer in Google. But speed is still an issue (Google has spoiled us on that front).