I spent 90 minutes in the lounge on Thursday evening - from about 5pm to 6:30, prior to the BA15 flight at 7:20 to Sydney. Had eaten and had a couple of caipirinhas at the QF lounge before entering, so was checking the lounge out more than anything but also hoping for somewhere quiet as I know from experience the QF lounge gets very noisy and crowded around this time.
I was only in the main lounge. No access to the CCR.
I like the BA lounge, for comfort of seats, general atmosphere and peace and quiet. Drinks and wine are good, but food is poorer than QF. Only one experience, but that's my initial take.
Comfort/Seats - layout is a bit odd, given it's a long and reasonably narrow lounge - so seating is pretty much in aligned rows / blocks. But there's a good mix of seats, couches or single armchairs, bench seats near the food, computer desks as well as empty table positions for laptop use. Reasonable space between seats and enough space for bags. Plenty of universal power sockets and USB ports next to every seat best I could tell. No true 'solo' seats, so you were always taking up 2 seats (or would have someone next to you if it got crowded). I sat first on a couch, then moved to a brown armchair in the far right corner. Both were very comfortable. Also sat briefly at a computer and at the laptop table. Well lit and fine.
Atmosphere - very, very nice. Nicely lit. It was also very quiet. That said, it probably has more to do with the fact it was only maybe 30% full at its peak, there were no children or large groups. A couple of times the TVs got loud and sound seemed to carry right to me in the corner. Given seating rows and with few zones/barriers, sound could be a problem if circumstances were different. But it felt more refined and peaceful (my preference for a lounge).
Food - ok but not as good as EK or QF. Lots of packets of nuts and crisps which you could take with you. Finger sandwiches, a soup, some nice cheeses and cold meats. Not much in the way of salads. Mini chicken pies, as well as mini pizzas. Chicken satays with peanut sauce and a 'salsa' which was basically diced tomato, cucumber and onion with nothing added. There were two hot dishes in the buffet. I think one was a curry, one a western, plus rice. Some cakes and small sweets. It all looked fresh - but all I ate were a few satays (excellent, though the salsa had no taste) and some cheese and crackers. I'd say they've got a way to go to match QF, let alone EK (or others which I haven't sampled).
Drinks - all self serve so make your own coughtails from usual ingredients. Good quality spirits and a wide range. Quite a few beers. I thought the wines were good - 4 reds, 3 of which were Aussie, one French. 4 whites. Sampled one Shiraz which was excellent. No champagne.
Bathrooms clean with an attendant who made sure everything was well maintained and clean. Did not try showers. A few newspapers and mags available - not a whole lot.
Staff were friendly but understated / unobtrusive. Not proactive in coming around to check or offer anything.
All up, a pretty good lounge. I was perhaps lucky to be there at a quiet time. I rate it better for ambience than QF, but below that for food, but it would be where I'd end a lounge crawl when flying OW.
Still prefer EK - for variety and quality of food, consistency of good service, and view.