Agree with many of the best lounges.

As for worst, at least for major international gateways, I'd nominate the SFO BA lounge, which CX shares. Nice staff, but the J lounge is on the cramped side for the traffic it generates when in use. And the F lounge falls even further below F standards, constituting just a modest-sized room. Neither has much in terms of food offerings.

Having said that, it's somewhat understandable that it's no great shakes, given both airlines' limited use of it for a total of only a few (four?) flights per day. And the one upside is that sometimes you can board directly from the lounge.