Hi Rab,
as a new starter last year I acquired 1 colony on brood and half which I struggled with and after it swarmed i reduced it to a single brood. I had 6 national single broods over the summer and reduced down to 4 for the winter.
Then along comes an offer of 6 hives, 4 of which are 14 x 12, also 3 nuc's which again were all 14x12. I found these frames easy to get on with and felt they gave plenty of space for the bees and contained them in a single box, thus doing away with my beginners bad experience of multi box brood nests. To be fair I was running long before I could walk and within 4 weeks of me getting the hive it swarmed on me following the warm spring followed by the poor early summer which kept me as a new beekeeper from inspecting.
I am changing 3 of my nationals over so I can run 6 14x12's and 4 Nationals. The 14x12 I see mainly as my honey bees and the nationals will be primarily for nucs and queen rearing, with maybe a bit of honey. I may in the end go all 14x12 but still make nucs and do AS with the nationals.
Following my recent bee farming experience I really liked the Poly Langs and would of considered them seriously knowing what I know now......... ahh hindsight.
I have though done a deal today for a un used Poly National, complete with 3 supers (no frames) for £50 from a local keeper who brought it last year but just dont like it.
So I will have 1 Poly for now. (might get an eke for it though and make it a 14 x 12 !
Cheers
Pete D