I've been using Bing (and IE) for a few months now, after years of Google and Firefox.
I'd guess about half of my searches go like this:
* type into URL bar
* get Bing result
* after a quick glance: decide that result is useless
* copy/paste into Google
I'd love to use Bing almost exclusively (especially since I'm really happy with my Lumia 630), but it is really frustrating sometimes.