I bought the Ryzen 1700, 1800X and 2700X. Looking to upgrade to one of these, but will wait for benchmarks, AMD is really on a roll. The 3950X is extremely tempting especially considering I can drop it right in my existing AM4 motherboard. Allowing backwards compatibility where possible was the best move they made. I would've bought 1 CPU from them instead of 3 (and soon 4, and then 5 with Zen3), without it.
zen3 would most likely be on a new socket, AFAIK. Zen2+ (4xxx series) would most likely be the last cpu for AM4, as amd have stated they will keep sockets for 4 years but that's OK since intel change it about every year or so..
I myself will be upgrading from 1700X to Either the new 8 core... but the 16 core looks so sweet...
AMD's slides showed Zen3 as the next release (Ryzen 4000 series), as 7nm+/Zen3 in 2020. Zen2+ isn't a thing, unless AMD is simply calling it Zen3. I'm not sure the names matter, as Zen+ was better than I was expecting with the XFR2 changes, so I bought one. From what I can tell, they tied support to DDR4 support. I'm expecting Zen3 next year to be the last AM4 CPU.
Doesn't really matter to me, with the value they've been delivering since the original Ryzen launch, I see no reason to not buy them all. People appreciate a good discount on a desirable CPU on Craigslist when its time to upgrade. It's just an easy swap, especially if you use an IC Graphite thermal pad instead of thermal paste.
