The primary difference between a 27# and a 36# is that a gusset has been added to the aft end of the 27# to allow extra lift. Otherwise, the profiles are the same, so you don't have the air-trapping and drag problems you'd find in a 45# vs. the 27#.
There is a difference in price between the 27# and 36#, if I recall correctly, but I don't remember how much it is.
So the question is whether you're likely to need the extra lift of the 36# in the future. If you decide you want to dive dry, and/or with a heavy steel tank, you're better off with the 36#. Otherwise, there's no reason to spend the extra cash.
There is a difference in price between the 27# and 36#, if I recall correctly, but I don't remember how much it is.
So the question is whether you're likely to need the extra lift of the 36# in the future. If you decide you want to dive dry, and/or with a heavy steel tank, you're better off with the 36#. Otherwise, there's no reason to spend the extra cash.