Re: metal or rubber mpc for bari?
Everyone all this forum will have their own opinion, but it's going to be based on how they play. If I were you, I'd try each for a while, and decide myself.
I personally think metal sounds pretty cool on bari, but at times, it doesn't fit the music. So my advice would be to buy both. Maybe a metal for jazz, and a hard rubber for legit. And maybe even another hard rubber for jazz. I don't play bari much, and when I do, I use a hard rubber piece, and that takes plenty of air, so I would imagine that a jazz metal piece for bari would take a very large amount of air. You may not even be ready for one(though I don't know your level of playing).
Hope I helped,