Had a pair of BD with the snap lock..Broke the snap loc quick...liked the stiffness of the ellipse and wanted collapsable poles. Went w/ these...so far they are great...only about 50 miles on them now...if you are into poles that telescope these are way stiffer and stronger than any round screw shaft poles.
I'm impressed by BD's locking system. It seems to work better than the twist style used by many of the other manufacturer's (although it can still collapse if not tightened properly). The grips aren't as rubberized as other models I've used allowing extended un-gloved use without blisters. So far they seem quit durable, which is supposedly one of the selling points of the elliptical style. I've bent literally dozens of pairs of collapsable poless over the years, usually in boulder fields. These seem like they might actually hold up. All in all very pleased with the purchase.