I have used these 2 and the Lupo for face and head for some time. Tried Gillette blades, UTSA, Crystal and a Shark. I get good shaves with all of them and rank them: OC, Lupo and Jaws. Haven't cut myself yet, and do get some irritation , mostly with the Lupo. I have to admit, for my head-shaves nothing comes close to Karve OC "C" w 4" handle and for the face....I think all are equal....including Vintage Gillettes, FAtip, R41 and probably the favs are Schick injectors......
I have tried the Karve on my head many times. I have used the C,D,E, & F plates. This razor worked just OK for me. I got a decent shave but the irritation was more than I liked considering I shave my head every other day. For an open comb, I had my best luck with the Ikon, but for overall performance (closeness, efficiency, and lack of irritation) my Rockwell is the hands down winner. I am really hoping that the RR GC SB does the trick for me (on my head).
I have yet to go down the injector or single edge road (I can see lots more $$$ leaving me).