Let's admit they are indeed a must if you wish to truly get everything in FO:NV (unique weapons, alternate quest...)
It's just too easy to miss important stuff in this game.

I do heavily use guides as they let me get the most out of the game

Agree, disagree ,comments?
Write them down!

I have the guide for FO3 and have browsed it a few times, but haven't really used it - except once, and then it didn't actually help much!

I also think it's interesting how they claim to have played the games exhaustively, but presumably didn't have any of the bugs & glitches complained of by players ...

Well I can’t really see the point in this. Anyway I do not use any guides but I do in facts search every grain of dirt in every area. Because I can and I love a challenge.

I'll admit to using the Fallout wiki fairly often, to better understand the game's mechanics and how they work (even though much of it is still an unexplained mystery, even on the wikis), and when a quest has me tied up in knots. There are a bunch of them that are so convoluted and intertwined, you'd miss a lot, even after multiple playthroughs, if you don't do some studying. But most of the stuff in the game, I just discover on my own. Exploring is the main fascination of it, to me.

The wiki has saved me more times than I can count if you just want to know the truth. I try not to use it anymore than I have to but like op said unless you just play this game for a insane amount of time there's going to be a lot of stuff you miss without help.

I use the wiki some times if I want to check the rewards for quests, perks and their requirements, what an item does, etc...