I've done some beef and bison stock that was pretty meh for flavour. It got better once reduced and seasoned. But still sort of meh. Not sure why some batches turn out that way. I've been powering through my turkey broth, so time to throw in some beef bones in the pressure cooker this week. I do find that when I take the time to roast the bones first, it does taste nicer, but it only happens less than half the time for me.