Tentatively excited about these new exploration rules. I'm not so sure about the whole "DM draws the map" thing - classic materials (including the 1e DMG, B1, and B2) very strongly advised DMs not to help the players with the mapping. I'm skeptical of anything that goes directly against the intentions of the original designers.
The original designers didn't always do good design work, though. A lot of their assumptions don't apply today, or were bad even back then. Consider ideas like the "Caller", which has fallen by the wayside - it made sense for certain groups, but rarely applies now.
Intense mapping by players has problems. At its worst, the game turns into a discussion between the DM and the mapper, while the other players wait for something interesting to happen. In some dungeons, it turns into mapping lots of empty rooms before finally getting into a fight. I was running a 4e conversion of
Mordenkainen's Fantastic Adventure last Friday, and that's exactly what happened: the encounter count was very low compared to all the confusing passages and rooms the group had to go through, and so the mapper got to do stuff while the others waited around.
Running
Isle of Dread last year for my AD&D game was slightly more bearable, but did lapse into intense boredom as I'd say, "You go northwest. To the northwest are mountains; to the east is forest; to the north-west a river runs through a chasm" again and again and we'd have to pause for the mapper to mark that down. This was a game with eight players, so the conversation really was between one mapper and the DM while the other players sat back and waited.
It should also be noted that the advice in those early products was strongly slanted towards adventures in "megadungeons" and areas where adversarial DMing was pretty much a thing. The game is a lot broader than that today.
I would like the older style to remain as an option, but in general I'm in agreement with Mike's position.
Cheers!