Biztalk performance

Darren Jefford has a list of performance tips for BizTalk Server 2004 implementations, from the blog:
"Another issue that came up recently which I didn’t fully appreciate is how “expensive” Atomic Scopes are, don’t get me wrong, they’re great and need to be there but I’m increasingly seeing customers using them where they don’t have to – For those of you with a COM+ background it’s analogous to running your code within a Transaction, most customers didn’t need them but turned it on anyway causing significant problems"...