I personally got my start with D&D in the early 90s with 2e. After moving to NZ in the early 00s, I started playing 3.5e and then switched to 4e when that came out. I was playing in two RPG groups when the Next playtest was first a thing, but neither group picked it up immediately.
Group #1: This was my long-running group that I'd started in NZ with a 3.5e campaign. We switched to 4e and played that for a while. We also played SWSE and the first FATE version of the Bulldogs! space opera game. When one half of the Bulldogs! party betrayed the other and we ended up with a TPK of sorts, I offered to run the Mines of Madness playtest adventure as a trial one-shot. People seemed to enjoy that, but not everyone wanted to continue, and I wasn't yet feeling up to getting back into DMing, so another player ran a homebrew campaign using an iteration of the playtest rules. At some point, some of us also got inducted into the closed alpha playtest program. We stuck with Next as it morphed into 5e. I ran both Legacy of the Crystal Shard and Scourge of the Sword Coast but both campaigns ended in TPKs with players moving on. We've since gotten a more stable core group of players who grok the cooperative nature of D&D and have thus had more success in their adventuring (with Curse of Strahd being one exception - Strahd got the better of them in the end). Currently I'm running Dungeon of the Mad Mage for this group.
Group #2: I joined this group as a player most of the way through a long-running 4e campaign the DM was running. When it finished, the Next playtest was out, but the DM decided to run short campaigns using 1e and 3.5e first before running a conversion of the Age of Worms AP. We started that with the Next playtest rules and ended it with the full 5e rules. This group also got into the closed alpha playtest program and has also stuck with 5e. The core group of players has remained pretty stable over the years, with just a few people coming and going. We recently finished a remix of Descent into Avernus, and the DM is now running us through the Eberron Oracle of War AL series.
Group #3: After the full 5e rules were out, I convinced my wife and a couple who are friends of ours to play through Lost Mine of Phandelver. We got my brother-in-law to join us for Tyranny of Dragons, and then my oldest daughter took his place for Scourge of the Sword Coast + Storm King's Thunder. My middle daughter joined us for Acq Inc + Tomb of Annihilation, while my oldest dropped out after her PC died in the jungle. We're just about to enter the eponymous tomb. This group is much more casual and we don't play as often or for as long, so we haven't gotten through as much content and I didn't bother to enroll them in the alpha playtest program.