I am changing over to foundationless frames. All my supers are foundationless and some of my brood boxes.
One thing i have to say is that they seem to LOVE to build drone comb on foundationless frames.
I had 3 deep frames ALL drone, both sides. On my package that i hived 2 weeks ago they are doing better, there is some drone, but spotty, not at all like the deeps i have it in.
Kind of annoying, but it's liveable.