As I understand it there are different levels of how to implement SF3 protection.
One is to just protect the EXE, not too difficult to deal with. I believe Gangland and Singles are examples of this
Another method involves not only protecting the EXE but encrypting data files too, look at Dead To Rights for an example of that! The 'crack' was nearly a whole CD!
Then there are the 'emulated functions'. As I understand it from a reliable source, it's these 'active protected functions' in the EXE that are the bitch that has stopped the release of titles like Beyond Divinity, TOCA2 and Killswitch as they are time consuming to find/trace!!
Please correct me if I'm wrong on any of those points