I agree with most things previously said. I think in all three big alliances there are three tiers of airlines, top, average and low end.

In my opinion the OW top notch is CX, BA and QF.
Average is AY, IB, JL, LA&AA if you get one of the few new J class planes.
Low end are old AA, MA and old LA.

I don't know about RJ.

As far as I'm concerned, the average tier is fine, certainly if you get a decent fare. Those who are complaining about AY should bear in mind that every day there are still hundreds of flights accross the pond with the old club-seats (i.e. most flights operated by airlines from the US).