People rave about the build quality of KUL. I haven't tried them, but this is something I trust the GH hivemind on.
Go for Ducky if you want backlighting. They have a lot of different modes, and 99% of the time they are very reliable.
KBP... I only have the V60 Mini, and I am very happy with the build quality and the form factor.
I am curious as to why you don't want to go down the Ducky Mini path though.