It is bad. Search something simple like "How big is the sun?" on Bing. Then search it and compare it to Google. Also click images on both for the same question, and compare. Post back here on your conclusions.
As far as what
EliC is saying, he could be right. Verizon took away my option to have Google, or any other search provider as my default search, when I had my blackberry. Woke up, and (bam!) all that was there was, was Bing. You could still use Google by bookmarking it tho, but that was extra steps for no reason.
Unlike blackberry, Google is deeply integrated into Android. If Verizon broke Google integration, and replace it with Bing integration, then that would be worse then you think. That means even if you replace the widget with a Google one, (for example) it won't stop links in the browser from defaulting to Bing when you click on them. Another example would be Bing maps would open instead of Google maps. Another limitation would be Bing's voice search, which can't compare to Google's.
That search button on your phone would only open Bing search, A nightmare.