Been looking at a pair. Anyone here have them ?

I don't know if this will help you. I don't have the BD56-12XD, but I do have a brand-new Kowa Prominar Genesis 8 x 33 XD and I am very impressed. I have compared it side by side to a new Leica Trinovid 8 x 42 HD (not Leica's flagship glass, but a very good optic). To my eyes the Kowa is slightly crisper and I can detect no difference in brightness (supposedly, after about age 50 our eyes can't take in more than 4mm of light anyway). When I focus on small print on store signs, yard signs, license plates, etc., at the distance when the print becomes barely legible, the Kowa's give a slightly crisper image. The 8 x 33 is very compact and exudes quality. The eye cups and lens covers are very good. The rubber-type coating is very good and I like the color. As you might know, the Genesis models have two fluorite lenses in each barrel which I suspect has a lot to do with their clarity and brightness. I have an 8 x 42 Leica Noctivid arriving in a day or two for comparison. I expect the Noctivid to be superior to the Kowa, but how much? I doubt they will be $1500 better than the Kowa's ($2500 Noctivid vs. $1000 for the Kowa's). We'll see. I realize the Genesis is a different product line than the BD-XDs you're looking at, but I don't think you can go wrong buying Kowas.