I like the Chris king(?) top cap mounted thing. I use it with xlab cages and it seems to works well. My forearms are slightly too close for a bottle mounted on the extensions.
I use one and like it.
Mine did come loose after about 11 hours, so I ripped it of and threw it onto the verge. When I went back for it someone had nicked it so I got another one!
I like the Chris king(?) top cap mounted thing. I use it with xlab cages and it seems to works well. My forearms are slightly too close for a bottle mounted on the extensions.