The latest AHI driver for the AD516 does not require Studio 16 to be loaded in the background. It works just fine as a stand alone AHI driver.
I have used the Toccatta, AD516 and Concertio (all in the same machine) and they all run fine using the WarpUP engine at max sound quality with the max file buffer. It also works with lower buffers, but I figure I have the memory so what the heck.