AMD had a couple of big missteps - the K10 with the TLB issue which impacted performance in the first two steppings, but they recovered from that, and then Intel had a huge step in peformance with the Core2 lineup after Prescott melted (quite literally sometimes).
After that, AMD was always perhaps a half-step behind thru Barcelona/Istanbul - and Intel was doing their whole revised Tick-Tock development schedule - and then there was Nehalem, which in many ways took the design concepts of K8/K10 by moving the Northbridge into the CPU with onboard mem controller...
But, like x86_64, AMD did it first...
AMD also was the one that did a major architecture change with Bulldozer - cpu modules (two CPU's, shared cache with a share FPU) - unfortunately, Windows scheduler with Threads/Processes didn't handle that very well at first (MSFT did release a fix), which hurts reviews and public perception - but they were very much ahead of the game, because it's the same game that Intel is playing now with their low power cores (Silvermont).
And Intel was going thru Westmere, and then with the Sandy Bridge, Ivy Bridge, Haswell cadence, going from 45 to 32 to 22 nm nodes - their process team kicked pretty hard... only recently on the 14nm node they've struggled a little bit with Broadwell, but seems like they're getting that one sorted...
AMD followed up with Trinity, the first credible APU (CPU/GPU with tight integration) and Brazos/Zacate...
It's been fun to watch - AMD has some great ideas, but Intel is so tightly integrated between the core architecture teams and their process/fab teams - Intel hands down has one of the best fab/process teams in the world...
AMD has to do outside to GloFo, TSMC, or others, so again, they're a half step behind...
With the PS4/XBone, AMD was at the right place, at the right time... Jaguar was a very good improvement on Bobcat, and GCN was the right evolution of GPU scalability and both were at the sweet spot of 28nm (and TSMC was sorted at the Fab level). These are great APU's, and it's helped out AMD by being a relative commercial success...
I guess what I'm getting at it that AMD leads on ideas, but Intel leads on Execution...
AMD is fighting a battle on two fronts - Intel on the CPU side, and nVidia on the GPU side, and they're doing a credible job at it.
Intel is having to worry about ARM, but with Silvermont, and now Airmont on the LPIA side, they're getting close.. but if they didn't have AMD pushing them on the x86 front, we wouldn't see the big improvements that we saw with Ivy Bridge and Haswell...
Having AMD around, very important for the industry...