That was actually very helpful. Thank you. I had a suspicion the Black bird was more "efficient" or "aggressive". At this point in my shaving journey, I seem to prefer the "mild but efficient" razors.I have so many razors and I never compared them back to back. They are both nice but different. The BB to me has more audible feedback, and is heavier which is what I prefer, and not sure I’ll like the lightweight of Ti. I have 5 and 5-OC on the ERA and I think the BB is still more efficient and percievably more aggressive. I think the Black Bird is in another league to me at least. To be honest the Dart was such a nice razor but got discontinued but will be offered again in limited quantities. I also prefer the Dart to the ERA. Having said all that I still bought another ERA 4-OC and a spare 4sb plate. Sorry I can’t be more helpful.