I can see using these as a starting mag to drop on the floor without worrying as much about the mag or your floor, and to add some weight to the gun to practice draws. Hopefully, especially with 2011, you will be able to rack the slide keeping the mag in because I find that it is a big waste of time to take the mag out, rack for the first shot, and reinsert the mag every time. There are dummy type rounds that attempt to allow this, however none that I have tried work with MBX mags in my 2011s. I feel they may be useful for reloads particularly if you are trying to reduce wear and tear on the magwell and your mags, but I also think it is useful to get used to the feel of using a real mag loaded all the way up to train yourself to the feel of really seating the mag in, and the weight, etc., This is especially true if you reload to 155 mags. These look like 140 length, so the weight probably still won’t be quite right if you start with 170 mags, and reload to 155s for example. Hopefully the weight is realistic for a 140 mm mag.
I still think it’s interesting, though, and plan to buy at least 2 of these to try.
I agree with more realistic versions of the mags, and hopefully revision two will include 140mm Glock, Sig, and CZ mags, and 170mm 2011 mags.