It's also a taste thing; I gave away every metal cup I had because of it.

I think it is something to worry about, maybe not for one press, but a whole kitchen. Like it or not, there's nothing against glass, even what you would call negligible, besides durability. There's a reason scientific apparatus are made from it. It's not even expensive. Just be careful with it.

If you travel with your coffee materials, or if you have kids, there are other considerations.