This is an amazing product. I'm running the processor @4.7ghz all cores at stock voltage and I haven't passed 65 degrees on any stress test (Prime95, cinebench, 3DMark and CPU-Z). Ran prime95 for around 3 hours with 0 issues, seems very stable.
I'm sure I can hit 5ghz but it is absolutely unnecessary since all I do is play games at 1080p 60FPS, might try it in the future. Right now I am just amazed by how much I was able to overclock at stock voltage. Coffee lake is the way to go for gaming.
Oh and by the way, I'm not even using fancy cooling; I have a Cryorig H5 ultimate and still ALWAYS under 65 while stress testing.
10/10 product by intel.