Wouldn't know, I don't touch SBS with a bargepole after many sleepless nights of frustration with it in the past, its a false economy IMHO. Multiple eggs, single basket.
Try selling a multi-server solution to an SME, and see what looks you get as you quote them for hardware, licensing, and CALs for each part. You won't be walking out the door with a PO.
Anyway, I virtualise all my SBS servers, providing much better recoverability and alleviating the DR/BCP issues somewhat.