Illo is about right. The extra deep frames (yes, the 'deep' are the standard size!) are heavy and the bees do go through the winter without bother on the single box.
There are other downsides, like inability to swap frames from double brood boxes (or swap boxes around).
Overall it is always a compromise. And yes, more crop might be left in the brood frames (Finman always wants as much as he can possibly get) and you would need a decent sized extractor to be able to extract the extra deep frames, if needed (my nine frame radial with tangential screens does the job).
There are a huge number of threads already on the forum discussing the pros and cons and they would keep you reading for some time. At the end of it , it is your choice.