You clearly have well hybridised bees from a long way back which are well mannered. It is often the crosses between particular strains and the local mongrels which lead to nasty temperament on mainland UK. Your local strain has likely been bred over many years to aviod mixing of very different genes and so they breed fairly true. Think here the problems of growing seed from first filial hybrids as an analogy.
The beehaus is not a better development of the Dartington, IMO.
I use two Dartingtons which I made myself and also have a beehaus. The Dartingtons get used, the beehaus does not. Mine is much better than as originally supplied, but that is another matter.
The benefits of the Dartington are manifested right from initial cost through to practical use
I clearly run 14 x 12s as my moveable hives, but as a sedentary hive, the Dartington has some benefits - along with some downsides, of course (as do all formats!). Those half-supers are nothing more than a pain - I use National shallows. They were designed as small enough to transport up to and, more importantly, down from a roof site.
They over-winter very well (a single colony in the central area) and. An build up remarkably early and well in spring.
One expensive pain may be needing to extract honey from 14 x 12 frames, if using an extractor, as not all will accomodate the large frames. My 9 frame radial Lega extractor works just fine.
The 'hairy-fairy' inspection tray on my beehaus was utterly useless - but you would not need that facility for checking varroa, anyway, while your area remains free of the scourge of the mite.
Any questions, prolly best to PM me; most of my earlier comments on this thread still apply, I would think.
Do not be fooled by them telling you it is really two hives. It is not, and problems will inevitably arise by keeping two colonies in the one hive.
RAB
