The Advanced Game

Using the 1st Edition Rules
Having cut my teeth on White Box I was never quite sure what to do with the Advanced rules (beyond admiring the awesome cover art). We played with the Advanced books at the table, consulting the hardcover PHB tome for spells and chargen, for shopping and weapon damage, for monsters we looked into the MM and for advice and all things wonderful, the DMG is still a treasure trove. We used it all and none of it strictly by-the-book. We improvised, smashed versions together and made it all work with rulings. As referee I tend to continue to rely on the Little Brown Books as my go-to rules, borrowing freely from all later Editions. Generally it has caused few issues over nearly 40 years of gaming.
Looking at the PHB, there are sections of the rules I have never used as a referee and seldom consulted as a player in another referee's game. Spell components and casting segments come immediately to mind. Some of the components add color to the spell casting and magic "feel" of the game, but the bookkeeping seems too much to bother with. The weapons verses armor class matrix seemed to be for someone other than our group and I only recall using it a couple times.
The lack of combat tables in the PHB (they finally appear in DMG) meant that for a couple years at least we had little choice, but to refer back to earlier rules to resolve every sword swing. The change from an unarmored peasant being AC 9 in White Box to AC10 in the PHB is annoying (maybe because I have never read an explanation) and I usually ignore the difference in printed play aids.
There is a bit of irony in the stated intent of the Advanced Rules to be more standardized and official, to allow everyone, everywhere to be playing the same game with common rules when it had rather the opposite effect on our group (and I am guessing other groups as well). With the addition of the Advanced material we added diversity and became even more individualized in our play. Some players would allow half-orc and half-elf PCs when they refereed, others wouldn't (did anyone play 1st Ed. gnomes?). Some would allow evil PCs, some would enforce encumbrance (or try to), etc.
So I recall using the 1st Ed. Advanced rules to dial up the game. Strength bonuses went up (+3/+6!), magic enhancements on armor and weapons increased (+5!) and PCs continued to advance well beyond "name" level. More monsters, more hit points, more ways to roll up characters and more magic items. more, more, more. At some point this became obvious (and obnoxious?) and more for the sake of more became a topic of discussion. Then the "less is more" philosophy started to take hold and many of us began to dial it back remembering the real magic of a game with just Three Little Brown Books.