I tested around 300 CPU so far.
Terrible is 4.7ghz about 3%
About 45% can do 5ghz with delid. About 18-20% can do 5.2ghz with Delid (Xtreme Bundle CPUm is this one or above),about 4% can do 5.3 with delid and 1% 5.4 with delid. The above figures are 24-7 stable for Real Bench, XTU with 3D running etc etc.
The rest are 4.8-4.9 capable.
I have tried on some Z170 boards yes but not the Z170-E.
Lol, that's about £100k's worth of processors you've gone through.