Which is better - (3) 12v batteries vs (2) 6v batteries

Thanks a heck of a lot Mex. So "time" is the issue. Is a month between 100% enough if you are doing 85-97s? Is it still enough if you are doing 50-90s?

And you never did answer about going to a Float of say 13.4v after each battery has done its 100% and put back into a bank at that 13.4.

Is it ok to Float them all at once after each one has had its dose of 100% or will they still kill each other according to the "usual warning?"