Yeah Steve that the as sort of my thinking that I'd probably only take a few frames at a time anyway, as I'm not running a commercial op, but still didn't want to go full deeps. Also only going 8 frame weight is a little easier. I hadn't really considered WSP until I saw its 3/4 of a deep, and manly is only another 10-15% less, but WSP is available from all my local suppliers.
Only other detractor for larger frames is I'd like to try comb honey and have heard smaller frames are better for that, plus I want to go foundation less and wonder about the comb stability in the larger size.
As for the plastic boxes, not really my cup of tea, but I can see the benefits. How do they go in winter? Do they have an insulation layer? It's -1C here still this morning, with heavy frosts.