How many people throw spare balls (I'm talking plastic, pancake core, no XXXL's or anything like that)

I used to use one, and when I dropped to 15#, I never bought a new one.

My question is, for those of you who own spare balls, do you think it helps your game, especially on tougher conditions, and if you own one, do you throw your strike ball weight, or one pound less (ie if you throw 15# your spare ball is only 14#)

I'm debating whether to pick up a 15# and keep my weights the same, or opt for a lighter 14#