Not real sure how you market your beef but if you're making $'s then you're doing the right things. When my Father retired he decided he wanted to try some Highlands, and bought a few. You're right they are very docile, but I never trust horns! I AI'd them for him and they calved easy, with VERY low birth weight. I moved them into the feed lot and watched their ADG weekly. I don't have the exact numbers here right now but as I remember it would take 700 plus days to bring them to harvest. Long story short, Dad moved them to the freezer. Fact was they were tender, not much fat or marbling. Didn't have that pretty red color, a bit more pale in color. Taste was ok, but not what I (personally) would pay a premium for. As for which bull I'd pick... being you're not looking to registered cattle, I'd go black. He has more body mass and structure. The folks that said if you shaved the white one you'd be suprised are correct. Put the white one in a chute and feel his sides and rear hips, then do the same with the black bull. See which one feels more beefy. Additionally watch the calvine ease of the black bull. While the Highlands calve easy, it may be due in a large part to the VERY low birth weight, and smallish calf shape. IMHO go with what feels right to you and keep your neck above water!