If you use good RAM for Ryzen with proper timings, it would be about 8-10% faster on average in 1080p gaming, basically equal at 1440p. The 2700x would still win in heavily multi-threaded situations and performance per watt.
https://www.computerbase.de/2018-04/amd-ryzen-2000-test/7/#abschnitt_benchmarks_mit_uebertaktung
https://www.techpowerup.com/reviews/Intel/Core_i7_8700K/18.html
For me personally, I'd take the 2700x (actually would probably take the 2700 or 2600x but that's not the current comparison). It looks to me like Ryzen 2nd gen has closed the gaming gap such that practically no one would actually be able to tell the difference between the two when gaming outside of maybe a couple of outliers. For me, having the extra cores/threads would be of more benefit because I would notice that a lot more than the difference in gaming especially since I'm usually at 1440p and am GPU bottlenecked anyway. Even when I'm not, I'm pretty sure I wouldn't notice any difference at all between getting 100 fps with the 2700x or 109 fps with the 8700k OC (on average) at 1080p. If you play at 1440p it'd be more like the difference between 70 fps and 72 fps.
If you game at 1080p and you'd rather have the 8% extra fps and give up the multi-threaded advantage of the 2700x, then great, go for it, but I and others in this thread feel differently. There's no need to make it seem like intel rox and AMD is teh sux over it.