pfsense grade really. I have heard about vyos, but nothing more. Given that bpfilter & XDP is now in the kernel, i was wondering if there's something built on top of the latest and greatest.
The differences WRT kernel between various Linux distributions are likely not significant enough to matter for the overwhelming majority of users.
Unless you have "non-typical requirements", pretty much any of them will almost certainly be "good enough".
(Personally, my preferences are OpenBSD, FreeBSD, and OPNsense, in that order, but I'm weird. If I had to choose something built on Linux, OpenWRT would probably be the one that I'd reach for "by default".)