The only PARTIAL solution I found so far is to run the Unit Preloader 2.0 from the arcade section every time I start up Starcraft II and only after that start playing. This will pre-load all the missing assets in the memory so the game does not have to stream them from the hard-drive/SSD during game play. Please note that this will only work if you have the particular choppy performance/mini-lag/ stuttering the first time the game loads a building model/unit/effect etc.
Other threads describing the EXACT same issues :
EU forums :
Please Blizzard do something about this !