No Render here! : it's just the inverse of the screen of Moi :)
@Michael
Something curious in Moi with only the follow Image + one Baluster + one guardrail of 20 balusters
(on the image there are three but it's a collage for the 2 bottom)
moving all (Rot, move etc...) is some hard (slowly) !
all snap object disable)
Is the fact to stay in the same session and continue to move rotate etc...make the "undo" more and more heavy (in memory) and result a slowdown speed?

I link (bottom post) 1 baluster + "up guardrail" piece : is that the same for you?

here you can load the initial file + image : 800 kb zipped
http://www.divshare.com/download/329975-39b