Because I like the Uniboot, BIF cables better. It's not that any of the ones you list won't work--I expect they'd all work--but I like the Uniboot better. BIF means there's (almost) no limit on bend radius, Uniboot means that the duplex connector is combined into one, and the duplex fiber is combined into a single 2mm diameter jacket rather than two of them. I just think it's a nicer product all around, with a minimal cost delta.