Hope y'all are being facetious...'cuz I was...

Anyway...I've got enough data now to figure how things are going to look, at least for me. I've got three S7s in Labrador that are running at a 50% overhead, including power and psu's, based on the pool's production since the halving. Those particular units were ROI already, so that's a moot question in this instance. An S9 would run at the same absolute overhead as an S7, but produces around 12THs, v. 4THs. The math isn't complicated. It will make money on a monthly basis, as do the S7s.
The problem, of course, is in the ROI. Until Bitmain gets the cost down on the S9, I'm looking at running A6s instead. If I ran an S9 at the datacentre, it would take (given spot staying stable) around ten months for ROI.