My experience of KK products extends to three Snub Nose fermenters, bought from Brew2Bottle. The whole purchasing experience was not good - one of the fermenters had a fault which has never been resolved (despite assurances on this forum from the claimed new owner of B2B), another had a missing cap gasket. I would say, having had experience of KK and Kegland, that the much trumpeted (by some) superiority of KK gear is cobblers - their stuff is not made any better than Kegland, and suffers from much worse after sales service. Spares for KK fermenters seem to be non-existent (even on their Australian website) whereas Kegland supply all the bits needed to keep their gear going, and at reasonable prices.
I still prefer my snub nose fermenters to the Fermzilla ones I had before, for several reasons, but I do not feel inclined to invest any more in the brand. Several members of this forum have given assurances about the future availability of KK kit (whether these claims are based on genuine inside knowledge or something else one can only guess). Kegland kit is good, it is subject to constant evolution and, more importantly, it is here: why wait for the fabled arrival of a mysteriously delayed KK container?