Well, I am a noob and a "McDiver" grad, but will throw my 2 psi in here about the slams on "McDiver" courses:
Scenario 1: Two already water-comfortable people intensly & thoroughly study their PADI manuals for 4 weeks on their own, learn how to work the tables on their own by reading the book & figuring it out themselves so they really understand how it all works - read scubaboard, etc, etc - make 100 on their written test with no cheating - go for a two day "McDiver" PADI OW cert weekend at local lake that includes all pool work & OW checkout dives - get their C-Cards, buy their own entry level equip.(inclu tanks after research & consultaion with others- practice in their home pool - make the effort meet up with other active divers in the local dive community & do 10 OW dives in the first year at local lakes/quarry/etc (+ several more on their 1st dive vacation that summer) - continue to read ScubaBoard & other sites, books, etc after the regular warm dive season is over
Scenario 2: Two OW divers (maybe one or both not entirely water comfortable) take a 4 or 6 week course, 2 nights a week at a local LDS (pick your cert agency PADI, NAUI etc) (except GUE of course) - miss a couple of nights, half pay attention during class sometimes, an instructor walks them through working the tables but they really don't understand the concepts, maybe don't learn tables at all, make an 85 on their written test - go for an OW day at the local lake get c-cards - immediately take a 3 day trip to Coz and go on half a dozen Coz DiveMaster led trust-me dives in rental gear - don't dive again for the rest of the year, read about any diving, or really even think about diving.
Who do you feel better about diving with next May? The "McDivers" or the "traditional" course folks?
I submit for all of your esteemed and experienced consideration the theory that "It's not so much the Agency or the Instructor, it's the student!"