I have a few to use as I bottle condition and I like to see when I'm carbed up. But I find them generally a pain in the neck (ha) to cap, so not in general use for me.
Ahh sorry, the version I have is a crown capping one, not a screw top one, so they get a bit squished under the capper. Maybe I should try the screw cap kind, but I only use a few anyways.