Sadly most of the "real" pianos that still survive in pubs, having escaped the piano-smashing furore of a couple of decades or so ago are NOT well maintained, and are out of tune, not just with themselves, but any other instruments in the pub, or have sticking notes, missing ivories, etc. I occasionally play one in a music pub I go to, but only at times when there's not much else doing, and it will only be a quiet slow air, none of your mad honky-tonk or ragtime stuff. As with any instrument in a session it's a matter of listening to what else is going on, and knowing when to play and when NOT to!