[madjockxbmc]

I'm using KODI 18.1 x64 with external players.  I haven't experienced any instabilities (except iso stacking which I've never used past or present) or found anything bothersome reported by others since they were addressed prior to the final release.  Refresh rate matching or postage stamp resize is not an issue here anymore fwiw.  Maybe many of the problems still reported are unique to some users approaches vs others?  Just want to emphasize there are SUCCESS stories too.  I see no reason others should be told to shy away from upgrading especially those who might consider using external players.

I've welcomed many of the new additions v.18.1 x64 offers.  UHD HDR playback with VideoPlayer for one.  Ashlar has asked if LEIA handles HDR10.  For me it does.  Butter smooth, great clarity, saturation, highlights and color.  It looks exceptional actually although I prefer an external player with a madVR renderer to passthrough HDR using a private API - nVidia.  My CPU is 10 yrs old.  So is my MB and RAM.  I have DXVA2 enabled and pixel shaders set as the renderer.  I don't toggle any O/S HDR switch off or on.  It's always off.  Using a blind test, I'd bet many of you wouldn't notice using KODI's internal VideoPlayer vs DSPlayer, or any other players tbh.  Yet for those like myself seeking absolute perfection, no single player is going to cut the mustard.  A combination of players will though and you will be state-of-the-art keeping up with the times and all it offers.

This all makes no sense, you say you have no problems with the final release yet you are using 18.1, and if you think UHD playback is ok, then you are quite mad.
EDIT : Just tried latest nightly in Portable mode and a couple of UHD HDR remux files. It is far from fluid and with Pixel shaders the colours are blown out and all too bright, so unsure what you used to say it is fine for the most part.