I've run just about every conceivable iteration of Mac small form factor, slotless logic board and compact Mac shell through the ole neural-network 3D modeller upstairs over the last few years. That's not the point of this thread.
Slots. I demand SLOTS!!! }
[/lightning]Although I admit I hadn't considered the B&W G3 - that was headed into a 1U rack/6100 case.