Of Minimal Use, IMHE
After 3 recent BF flights (EWR-ATH, EWR-ATH, ATH-EWR) my only encounter with one of them was to be informed that my vegetarian meal didn't make it on to one of my flights (we were still at the gate). I was accommodated by being given a pasta dish (one of the 4 regular choices).
Showers? What showers? I've never been offered anything of the kind in either direction. Likewise, I've never been directed or informed on how to get to a lounge after arrival. I've never received any help or direction on clearing customs. I've never received any help with baggage. In fact, I don't ever recall seeing a concierge upon arrival in any of these destinations.
I'm not saying that CO should get rid of the concierges, but if the rest of the staff treated BF customers like they were important, high-revenue passengers, CO probably wouldn't need them.
By the way, shouldn't a GA or an FA already know that they should do anything that they can for a BF customer?