Hi Dave,
I think they both cater to different modellers; there are those who will want the ultimate Lancaster and there are those who will focus on a good exteriour finish. I agree that the market for a 1/32 four engined bomber can't be all that big...
If I were in the market for a 1/32 Lancaster I'd go with the Border one, due to the massive effort required to finish such a big model to a good standard, I'd want the best kit possible even if it would mean selling off some stash to raise the funds.
The external finish of an HK will require an equal amount of effort, even if the internals are less complicated. Perhaps even more effort for the HK one, as (depending on one's standards) you'd need to make up for the lesser (IMHO!) external surface details of the HK.
I was very impressed with the video (I can speak and understand German quite well), but when I think about those millions of parts needing to be clipped, cleaned, assembled, base-painted, detail-painted, washed, weathered, etc, and only then there is the huge external surface of the beast, my attention span is far, far too short for that! So I'm not getting one of either. My current 1/32 A-6 Intruder build is about the limit of my attention span and effort, and that is "only" ~55x35 cm (35cm with folded wings, otherwise about 55x55cm)
Jeroen