I would always favor delay and recharge rate over capacity, to be honest. My advice to you would be to find the middle ground: a BBB that doesn’t have a ridiculously long delay (it’s almost 7 seconds on the highest capacity one, if I’m not mistaken) or a ridiculously low capacity. Go with the most balanced one you can find. I think the most balanced one would also have the highest recharge rate - but the lowest booster chance. Yes, you have the booster chance to consider as well. I never stopped to study shields as much as I should, so I can’t help you a lot with shield parts or exact stats. Personally, I only use the BBB on Fastball Axton. I can’t remember right now the stats on the one I have, but it does what it is supposed to do. For a less specific explosive playstyle, I’d go with a more tanky shield (Blockade, Antagonist, Neogenator, Evolution, a decent purple Turtle or even the Sham, for instance).