Peter, they do seem to be consistent between sets - I've yet to have a bad set. The only thing is the unwound strings, and I know people who say they've never found that so it could just be me :-/

I'd only play D'Addarios in public if each set came with a free gold-plated Ferrari with Michelle Pfeiffer draped over the bonnet! They're great for trying out instruments because they're utterly character-free, but by the same token that makes them the last thing you want to be using for actual playing.

Graham.