My visceral hate of Spring.Net burns with the force of a thousand suns.

Almost everything it does is done wrong or solved better by other solutions.

Specifying which classes to instantiate from .xml files? Sure why not, compile type safety (the whole reason for using a static programming language) is obviously overrated and dependency based injection is surely impossible!
And for extra bonus points, now our client code must be aware of the internals of the service classes, and all of their references as well, because, encapsulation? Who cares.

Have you made an typo? Good fucking luck finding out from which of the 100 config files we have floating around...

And, because it has baked in AOP and Transactions its woven into the fabric of the project like a tapewom.

Of course this may just be how our "special snowflake" project uses Spring.

What makes it more painful is that I love good DI tools (ninject, castlewindsor, autofac, there are so many...) and we're stuck with this turd because 7 years ago some java devs couldn't be arsed to learn a new library...