Bing does far less word-stemming in my experience which is probably because of inferior technology but it's often a more desirable result.

For instance if you search a weird business name, Google tries to make it into more statistically and phonetically common words. Bing gives you more of a literal search. So they're going to wow a proportion of users who find that's what they want.

Google is so annoying sometimes with word-stemming. You used to be able to use the + sign to turn it off. Then you had to use quotes. Now the quotes don't even seem to work. Sometime Google is too smart for its own good.