Props to Ms. Bond for her time and effort in exploring an alternative path to gain experience. I am far more impressed with her efforts that that of the AQB and PAREA.
Here are my observations:
1) The success of the program is heavily weighted on the skill of the Instructor (Mentor in the case of PAREA). I do not know Ms. Bond personally but I would make the reasonable conclusion that she is a highly competent appraiser being that she holds an SRA, works for a state board, and is on the ASB. With these skills, 60% (12 of 20?) of her students were able to become licensed (based on the OP's comment, someone correct me if I am wrong). PAREA has virtually no standards to be a Mentor. The standard is the same for that of a Supervisor which is to say one must hold a Certified credential that was in good standing for the last three years; this is well over 50% of all credential holders, nationally, and is a very low bar.
2) MPAT received a grant from the ASC. This makes it sound like it was just free money. In reality, this grant money is from the fees pais to the ASC by credential holders, including AMCs. Effectively this program is paid for by you and me. It is not free money. Without outside money, how many will sign up using their own when the success rate is 60% and your most likely source of earning will come from AMC work? (We're not taking about passing the BAR and making six figures in a few years.) Even worse, vendors offering PAREA will undoubtedly peddle the course based on some metric of success rate ("99% success rate", "take the course until you pass"). Financially, course providers will engage and then filter Mentors who are eager to keep their jobs and offer the highest pass rates.
3) A State run program like Mpat would likely have solid oversight as the head of the state regulatory agency would carry the burden of a failed program. Even better would be a co-op between the state regulator and a state school such as a junior college. With PAREA, there mostly likely be a misalignment between the aim of the PAREA course provider (profit) and what should be the goal of the PAREA program (appraisal competency). This in and of itself, is almost always the case for educators. But in this instance, the AQB have set virtually no firewalls in place, only that it, the AQB, will monitor PAREA providers via audits and respond to complaints by students. (To this end, I have commented and offered suggestions to the AQB without a cogent response.)
Overall: There is grossly insufficient information available to determine if MPAT or PAREA will succeed. Either could be a fantastic alternative to train new appraisers or a complete failure for the industry. Of the two, an MPAT appears to have far more possibility of success. Regretfully, the "trust us" approach taken by the AQB makes me worried for the future of the industry I've been in for 38 years.