As a BizTalk consultant I have to agree at least partly with Eric Z Beard, there are a lot of edge cases that take up alot of time. But quite a few scenarios are handled extremly smooth as well, so it all depends IMO. But when you (Eric) call BizTalk bloated I have to disagree! We've found that the performance and reliability is excellent, it's flexible and comes with a lot of good adapters out of the box.