Thanks for the reply George,
Unfortunately I am already using the Autodesk recommended way of using HDRI's after watching their youtube video on introducing IBL method as it seems to work best with HDRI workflow. (Skylight is using scene environment) I never had problems with normal interior renders where soft shadows are more desired, only with strong sun + shadow HDRI.
I just did a few tests with HDRI placed in Color Map slot for lighting + HDRI instance in Environment Map = same speckly reflection as I posted before.
Another method I tried, is just keeping HDRI in the Color Map to only get lighting from it, and removing environment map completely. I'm still getting strong shadows this way with no problems.
So now I know it's the issue with the Enivornment Map when it''s using HDRI for reflections.
I managed to achieve a more desired look by Creating 2 HDRI materials, keeping original in Skylight- Sky Color Map- so it won't use it for reflections. Then creating a copy of the material and setting Bur value to 100 and placing it in the Environment Map slot. This way there's no more speckles from the sun...The lower the Blur value the more speckles I get, hence why 100 produced best results.
However this is not an ideal solution, as now any other material, like chrome would have extremely blurred reflections- so clouds would simply blur into the blue of the sky...pretty much pointless?
I just had a EUREKA moment.
If I load the Environment map HDRI as 16bit and not 32 real Pixels (in the Setup of HDRI load settings), I am still getting correct non-blurred reflections without the speckles! So I just need to have 2 seperate HDRI materials, one at correct pixel depth and one lower.
This solutions works so far, will have to test it further at work, but I hope everyone else can find this useful too, because I spent so much time searching for answers on this issue )