After reading the horror stories about dialing in a good tone on the IIC+ I was prepared for the worst. However, it turned out to be as easy as pi r squared. I'm a fusion guy, so this won't work if you're a headbanger. I took the USA Lead preset and changed the amp to the IIC+ Deep. Then I ditched the stereo 4x12s and replaced them with an EVM 1x12 (Factory Cab Eight). Bumped up overdrive from 7.5 to 8, reduced bass from 2.75 to 2, hit the Fat switch. Presto, change-o, beautiful, rich, singing fusion lead tone on my PRS 513 bridge humbucker. Satisfying enough that I played it for two hours straight without changing a thing.
Edit: Fyi, I've never owned a Mark, although I did have a DC-5 20 years ago that was killer.