did try beta branch, steam user
campaign mission 1 Folsom: took longer to load i thought it crashed but it came through, i had troubles with first step zoom in ( would not let me zoom in enough, but after alt+tab and back it worked, or it needed more time to load everything )
played 1 skirmish game vs ai, GS vs SH, everything seems ok
edit
on second start it loads faster, zoom in works
can`t download maps
Did run few multiplayer custom games 4ai vs 4ai, no lag, works fine