I experimented with single brood chamber 10 frame deep hives this year, I tried two hives this way. It definitely takes some attention but it is actually fast since you only have to deal with one brood box. It works good. Pulling a couple frames of sealed brood above the Queen excluder quickly teaches the bees to pass thru it too. This was a late, cool, wet and odd spring, swarms were a month to 6 weeks late in Ohio. The two brood boxes I tried as singles never swarmed, they had a few cells started and I kept them scraped out.
Now I am deciding how to approach winter. I have over wintered singles a couple times and think I will try again this year. We are in a very good Goldenrod flow right now. I will pull all my supers in a couple weeks and allow them to finish back filling the single box. I will feed extra if needed.
Overall, I liked the single brood box system this year and will continue playing with it next year.