I have been through EWR a couple of times in the last few months. The First lounge is separate from CW and very quiet. One trip was a day flight and there was a fair selection of breakfast items; no champers though. On the evening flight there was a shared dining room with CW. The food is fine and good wines.
One recent change is that you no longer have to go to check-in to have your docs checked; they do this in the lounge or gate now. (It used to be a bit of a pain traipsing downstairs and queuing). So go straight to security - you cannot get to the BA gate airside from any connections; so leave time to clear TSA.