These things have been around for a coons age, but have never really caught on. I think part of the reason is they are somewhat caliber specific, and really don't offer much more than a conventional Mil-Dot system, except for the fact they might be a little bit easier to use. I have also heard their quality was a bit spotty, but that I cannot verify either way. I know also they are quite expensive, and for the money you can get a comparable Leupold VX-III, or for a few bucks more a Mark IV.
Back when Redfield scopes were made here in the 70's, they had a ranging system avaliable as well. It involved too much monkeying around, similar to the Shepard system. You had to "fit" the animal between a set of lines beneath the crosshairs while turning the power ring up or down, then a little "yardstick" would pop up from the bottom of the field of view giving you a range readout. You then established any hold over based on that. This was all big stuff back then because things like Laser Rangefinders didn't exist. The problem with all of these kind of systems is by the time your done doing all of these things the animal is more than likely in the next county. Not to mention unless you have the stability of shooting off of a bench, or some other kind of stable resting system, it is all but useless. With modern Lasers being now incorporated into scopes that are fast becoming smaller as well as cheaper, these kind of gimmick scopes are headed the way of the 8-Track Tape Player. Bill T.