Actually both E11+ from Ebang and T3 from Innosilicon at 10nm both outperform the Bitmain S15 in efficiency, 48W/TH and 45W/TH.  Bitmain is around 50-58W/TH I believe?
And reading some reviews it is a very unstable and unreliable machine.  
So far only Bitmain and GMO have attempted 7nm tech. GMO was a total failure, as efficiency was close to 16nm. Only Bitmain came close but with a very unreliable chip.
For now I'm still running my S9's.  It's not worth the investment risk yet to upgrade with what is available in the market.
Hopefully they will improve but in these market conditions I seriously doubt it.