Does it work?
There have been over 200 studies on this style of training. Typically results have shown a 10-15% increase over the control group. This type of training is most effective as an add-on to a traditional program.
Because you are limiting oxygen supply to slow-twitch fibers it forces your fast twitch fibers which don't require oxygen to kick in even though you are using lightweight. This allows you to create muscle damage and muscle breakdown using lightweight.
The nice thing about the workout is that they are meant to be kept short and intense. Think no longer than around 10-15 minutes. BFR training is ideal for increasing lean muscle mass, promoting the production of growth hormone, and an active source of recovery.