I stopped putting foundation in my hives a while ago (see Frames without foundation). Foundation seems unnecessary to the low intervention bee keeper. Its principal benefit is to make extraction and inspection easier. I outlined in the article how shallow frames can be extracted without wired foundation. Inspection is also much the same. You just have to be slower and more gentle.
The hive still has frames, so I still want to be able to take them out. That means I need reasonably straight comb. Each frame has 2 lolly sticks which act as guides and anchors for the comb building.
The lolly stick guides have generally worked well. I've seen some very straight comb. I've also seen some wonky comb, where the colony built more slowly. I'm not sure why, although the wonky comb was in a persistently small colony whilst the straight comb was in a busy one.
I also hastily put in a super without any foundation or lolly stick guides. The result can be seen in the image. Very wonky, so that the comb is anchored to two frames. I harvested early so that I could reduce the height of Hive A. I couldn't put wonky comb in the extractor so I just cut it into slabs as comb honey.
EDIT 04/052017: Paul from my bee group tells me that bees build straighter comb when there is a consistent nectar flow. When the supply is stop-start the comb is built in stages and may be less straight and regular.