I'm using it, it works great. It Provides you the feedback that you need in order to speed things up during a type/or types of problem, it clearly defines strengths & weaknesses, with RAW data, such as percentage of correct answers, time completed, etc. The best method to use the OG Archer, is to do the problems on paper, and review the OG Archer, a day or two in advance before a test, and try to do as many problems as you can, and as often as you can.
This will reinforce the paper learning, and hone in on your timing strategy, and when you take the practice exam, you'll be more aware of timing, traps, patterns, and it will keep you refreshed on certain concepts that you might struggle with.