I would like to add something to the Pros/Cons of Grolsch bottles.
They have two types of seals. One is like Rubber and the other is like Nylon.
I'm thinking the Nylon type are better.
Overall, I recommend glass Grolsch bottles, as there is no metal to "rust" in contact with the product. Also, when empty, a quick rinse, drain for a day, re-seal, sterilise, go again when next ferment is finished.
I'm looking for some info on the two types of seals if someone can oblige?