But... well it seems that missing the playtest I missed part of the "5e story".
Don't feel too bad, it was kinda a chore, really.
So what happened? How was it run?
The first playtest packet was released along with a 'Caves of Chaos' adventure. Then there was survey, asking how you felt good a job each element of the playtest did at capturing the feel of the classic game, and whether it was over-/under- powered or just right. In the very first survey, a handful of not-exactly-classic game elements - spells like Thunderwave, Witchbolt, and Healing Word - were included in the choices, and, you'll note, they're in 5e. Only in the first survey, though, after that, it stuck to what was in the latest packet, and that was always stuff with some roots in older editions - the one exception being the Sorcerer which was intriguing but never got a second take in the playtest.
In a nut-shell, the Next (the playtest version of D&D) started out strongly reminiscent of 1e AD&D, experimented with a range of things to try to make martial characters competitive, dropped them all, experimented with a range of things to make it more 3e-like, kept a few, and ended up strongly reminiscent of 2e AD&D - but 5e turned out even more 2e-like when it hit the shelves.
Was it helpful? I know they were extensively debated at the time, but I am not keen on reading dozens (hundreds) of old threads about the topic...
I suppose it helped WotC or they wouldn't have kept at it for 2 years.
In fact, classes like the Bard, Sorcerer (except for one foray where they were testing the waters for a more 'radical' version of the class), Warlock, Monk, Ranger, and (I think, IIRC) Paladin were not even in the play test. I can't remember if they had the Barbarian.
Both the Barbarian and Ranger were in some playtest packets - the Ranger one player had in Crystal Staff seemed OK, actually, in contrast to the complaints about the final product. I have a vague memory of someone playing a Paladin, but it may well have been a Cleric tricked out to resemble one.
I feel they made the major design choices early in the playtest but you're welcome to disagree.
I couldn't explain why, maybe it was the way each successive packet felt in relation to the one before, but I got that impression, too. Maybe it was the way Mearls talked up 2e going into the process, and ended up with something that felt a lot like 2e. :shrug: Not really that important, whatever the degree to which the playtest influenced the design, we did keep the torch burning for D&D in those years it was off the shelves.
And, the result's been a success.