I'm not out to spark to pony/no pony debate (that's been done), but I would like to hear what your size preference is from those who use pony's. For some of the diving I want to do a redundant air supply is required. I'm looking at a 30cf but I am concerned that this might be larger than I really want to deal with. I'm planning to rig it under my left arm as a stage. I'd like to hear what size other people are using and what they think about the size. Thanks.