This recipe struck me as odd, but turned out quite good. It is also complicated, with a marinade, a spice rub, roasting, and then a sauce. I did not have a rib-eye roast, so I used a round roast and adjusted the roasting conditions accordingly (the less tender round doesn’t do well with high-heat roasting, so I used 350 degrees F, to an internal temperature of 125F). As you can see from the photos, the meat was a perfect medium rare.
I also cut the amount of butter in the sauce from 12 Tbsp to 8 Tbsp. That was plenty. The sauce was delicious, having not only alcohol to carry flavors, but that other great flavor vector FAT—and lots of it. Indeed, given the small amount of alcohol in dark beer, I would argue that the major flavor enhancement/solubilization/carrying effect is probably from the butter, rather than the alcohol. But enough scientific review-- it did taste good, whatever the reason.
The sweetness from the cider, plus the slight bitter note from the beer, and the richness from the butter made a great and unusual sauce. This recipe is too complicated for the result, which is just a good roast beef with an interesting sauce. The marinade did not seem to penetrate the meat and the rub was okay (but I prefer the five-spice rub from the Chinese-style sparerib recipe). But I would serve the sauce with a roast again, maybe.