The rumor was for the 3700x to have a base clock of 4.2ghz - I would guess that the RGT leak is around all core turbo. At 4.55ghz that's what 400mhz over the 2700x on all core? If single core mirrors that it would be around 4.8Ghz. Not too shabby if that is standard. Though if the 2700x is anything to go by the chances of achieving better results by overclocking versus XFR are slim.
It is going to all depend on the mythical IPC numbers to see where it sits against Intels top offerings.
Now we need to know if those figures relate to the reported B0 stepping or earlier samples. Factoring in slightly higher IPC and more cores for an equivalent price I can see Intel being matched and beaten depending on the benchmark. I think the 5GHz clocks may come with Ryzen 4000 tweaks.