Everyone keeps bringing up the 40% IPC improvement as if it's a good thing, but I'm feeling it might not be enough.
http://www.anandtech.com/bench/product/698?vs=836
Just multiply the AMD numbers by 1.4. This is not enough to even match Haswell from 2013. There would have to be a 60% improvement. They'd still be at roughly Sandy Bridge performance from 2011, or slightly below. Makes you wonder what the AMD engineers have been doing for the past 5 years if they can't catch up with a nearly stationary target.
I would love to switch to AMD next time I upgrade, but it should not be a step back in single-threaded performance compared to my 4770K from 2013. Of course, if Zen reaches 5+ GHz like Vishera, the gap would close, but probably at the cost of much higher power consumption and heat.
Also, did anyone really expect a proper launch of Zen? I thought it was common knowledge that Zen and Vega would be revealed later.