>a) any blazing advantages to one over the other?

No.

>b) I asked her to ask if both can co-exist on the same server

Yes, they can.

Both of these questions are actually rather long discussions, though. For specific requirements, one may actually be better than the other.

Blazing advantages depends on what you consider an advantage. I have a server out there that runs ASP, .NET, ColdFusion, and PHP all at the same time for various sites.

The technologies can coexist even if the developers can't. <s>