My spare ball is 1 pound lighter, and has been for roughly 10 years now.
In my case I have two reasons: 1) Yes, I do want more deflection for that dreaded 3-10 split, and 2) Because I'm using it to knock down very few pins (usually one) so I figure less wear and tear on my hand, wrist, elbow, shoulder, legs, over a lifetime of bowling... Timing is not, nor has it been, an issue with me because I'm not trying to throw it harder. To each his own though.
