I decided as an experiment to switch my default search engine in Firefox from Google to Microsoft's new Bing. That was last Monday; today I switched back to Google.
I made the switch using the Official Bing plug-in for Firefox and from then on I was binging instead of Googling.
The one-line summary: I found what I was looking for with Bing but I'm going back to Google.
Overall, Bing was an adequate substitute for Google, but didn't provide anything better. And in a few cases, it was worse.
I was able to find things faster with Google because the Google interface is cleaner. Although there's not much on the Bing page there's a distracting (to me) image at the top, the top menu fades into the colored background and there's an annoying left navigation thing that distracts from the main results. Visually these things sent my eyes searching around the page a bit more. (I think the 'related searches' on the LHS in Bing is a total distraction).
Here's a vanity search on Google (which I find easy to navigate):
And the same vanity search on Bing (lots of wasted space and a horizontal scroll bar):
However, the actual links that Bing was finding were just fine and in general I could easily find what I was looking for within the first five on either search engine. I didn't find Bing's cute popup page summary very helpful. I can usually figure out from the short summary below the link whether it's worth clicking on.
Bing really fails when it comes to news. It has no equivalent of a Google News search. Obviously, I'm interested in news stories about my book, The Geek Atlas so here's the search I do on Google News:
And here's the equivalent for Bing:
Also, Bing's image search is poorer than Google's. For example, when searching for images of a chi-square table on Google I get this:
With Bing I get irrelevant results and a horizontal scroll bar (yuck):
Overall, Bing is a worthy competitor for Google, but it's not worth switching to. Perhaps it will be one day.