So, my experience with Memtest has been a roller coaster ... and that's not saying that was exciting in a good sense.
I got the Xtreem 8Pack 4500 and was hoping to get some stable 3733 14-14-14-28 timings on it ... and oh boy ... how wrong was I
At those timings, Memtest said that everything was peachy ... 300+% coverage, no errors ... Even Prime95 large FFTs were ok ...
I started playing some games and I got instant reboots ...
Tried CB20 and 4 out of 10 test would give me errors ...
Run Prime95 Blend and workers would stop ...
So my question is ... how stable are some OCs I see on some youtube videos and so on ... They pass, Windows performs ok, but as soon as you start stressing CPU, IMC, and Memory, things break
So, right now, I'm at 3733 14-16-16-32 ... no crashes yet ... let us see.
Oh... right, something I forgot ... Dram Calculator did nothing for me

I already identified that some of the secondary and tertiary timings are the ones causing the instabilities, and those were almost a copy-paste from Dram Calculator ... so for now, i just hard typed the default values and will change 1 by 1 and tryout with Prime95 Blend and Gaming ... it will take ages but at least it will keep me engaged on this memory OC and learning more and more