After about 15 years and at least one valve rebuild my crack bottle DSMB is at the end of the line as it is no longer sealing properly and the blob is now basically faded from "international orange" to "lo-viz white". In terms of pence per use I am well ahead of the game (I estimate it has cost me less than 10p a dive!) so the obvious thing is to buy another. However, I am thinking about going over to CO2 simply because they are smaller in the pocket but I don't actually know anyone who uses one - so are there any views/recommendations etc. from the TDF hive mind?