beo, i wouldn't consider these ridiculous gains, just consistent ones. before when i was doing a traditional 'kill the muscle once a week' programs, i was a lot less knowledgeable about progressive overload and it's effectiveness. i used to be of the mindset that i wouldn't go up in weight unless i got 6 strict reps with the current weight. and so, i'd go up and a lot of the times i just couldn't exceed 4-5 no matter how hard i tried or worked at it. then i started reading DC's cycles for pennies thread and i picked a few things out that made sense, i.e. - the same exercise can't work forever or we'd all be leg pressing 50 plates per side by now. change is a necessity. so, i took that principle and mixed it with progressive overload and it has worked wonders. i'll never drop squats but i'll never do the same weight two weeks in a row either. if i get 495 x 10 one week and get 505 x 8 next week, that's ok - keep moving up by 10lbs each week regardless and you WILL surpass your previous PR once you work up to it again. however, i wouldn't advise progressive overload for every exercise, just the main ones. i've tried it on smaller muscle groups and it doesn't work that way, lol.
brick, yes. i work up in weight with low reps until i get to my 'all-out' set. then, it's balls to the walls go until you can't go anymore. if for some reason you don't beat your previous rep scheme, it may be time to drop that exercise and move to something else, as per DC protocol.