Ah, but mortgage acceration requires a modicum of fiscal discipline, which many households lack.
In the end, the most beneficial method of payment is the one that the borrowers actually STICK to. A lot of my working class folks (W2ers that count on a refund every february) make that extra payment when the taxes come in (more or less at the beginning of the year) - money they never really counted and spent.
Those that have trouble parting with large sums of money do the every 2 weeks thing, because it "feels" the same as the regular monthly payment. You can often determine whom is of this mindset by whether they think there are two months a year when they receive an "extra" paycheck - as sure sign of paycheck to paycheck monthly mental budgeting.
The best way for an average person to pay off their mortgage early is to make that system of early payment meet them in the middle in terms of they way their view their finances. . . . the true "wow" factor . . .; meaning it didn't feel "hard" to do it. Nothing against the average borrower - some love the calculations, I'm one of them, and I was even before I got into this biz, so I love the acceleration concept - but some do not like to think about it, and the "easiest" method of smart debt service is the best (most motivating) method.