I used B3R Pioneer Wave on heifers a couple years ago. Had good luck with calving them with no assistance needed. I agree that they didn't have a ton of gas, but wasn't expecting anything high octane. Didn't keep any heifers, but I think they would've made good cows. All the PW calves were fed and sold direct. I will say that the PW calves had beautiful steaks and the RE were pretty big. A couple of them had 1 1/4" thick ribeyes that weighed over 24oz. Never did get a chance to sample one for myself, they sold QUICK! Would've loved to have snuck one on the grill to see how tender they were. Folks kept coming back for more of those "steaks like you had last time". I haven't used him again, but not because they were less than what I expected.
I'd expect that B2B would make some dang good cows, but probably smaller than most. I'd put him on some cows with some gas in the tank (and some frame) if I planned to keep any replacements from him.