Diving Doubles, and how much does size matter?

[Chris H]

I have steel 80s, 95s, and 130s.  All have been on some great dives.  I prefer the 80s.  They aren't ideal if you are doing 2 dives in the 200ft range.  There isn't enough gas for me.  However, if you can use an aluminum 80 as a bottom stage on one of the dives that helps some.  If I had my choice, all of my deco dives would be with my 80s, and one or two 40s for deco gas.