Yeh, its pretty bad.. I made 1 tiny area, and put 3 placeables, then you gotta 'bake' the placeables to the ground (like rendering) and takes a LONGGGGGGG time. It would be a freaking NIGHTMARE to bake a level as big as level one Undermountain. You'd seriously be sitting waiting for it to 'bake' for 5 hours.
Total bullshit. Whoever decided to use this moronic way of doing things need to be fired--deep into the ground.