Sticking with one brand

IMHO, sticking with one brand has the advantage of providing a base line. After that, you will have a clearer understanding of what cables (quite possibly different) work best between different components. Though it can be challenging to actually extract opinions from often times diplomatic and/or dealer sympathetic manufacturers, finding a consensus from amongst the different maunfacturers of your system can provide a very helpfull start. Bear in mind that some components, like some gear from Naim, Spectral, etc., for example, may have unique requirements that limit choices.

If you enjoy the transparency that the Kimber line provides- Why change? I've experimented with a number of other companys over the years, but always come back to Kimber(now using their Select line). Their stuff just seems to get out of the way of the signal so much better.

AFAIK there's no special reason to stick with one brand... unless your system sounds nicer (to you) that way. Try it and see.