The frustration comes from how easily MS Live is gamed by dishonest webmasters and how quality sites are sometimes banned from their index.
I gave MSNdude an example about a year ago where one webmaster had about six of the top ten results for a phrase (identical pages with a variety of domain names - all supplying useless data pointing back to a primary domain). The problem was fixed (manually) but that fix was only temporary.
If you ask MSN why you're banned they are clueless. I posted my experience with MSN which was extremely frustrating and dead-ended. To this day I only get that stupid quality check robot which doesn't do anything to get a site un-banned.
MS can add all the bells and whistles they want, the SE's overall quality is poor.