If you are using the lighter ball to throw dead straight for spares, not much of a con. You may over throw the lighter ball but that wpould only be a concern if you are trying to use it for something other than hard and straight

I am new here.
I bowled all the way with 15 lbs. Once got injured and had a time go down as low as 12 lbs.
other than that, 15 lbs is my weight.
But lately a coach advised me in trying 14 lbs.
What I felt is:
14 lbs, I can control more on the ball, fingers, wrist....\while 15 lbs feeling is kind of it weight me down on everything, the swing, fingers,,,,,,,
one example is: with 15 lbs, may be psychological effect, the placement is small, my elbow is not straight, and the hand grip it tight, then, the back swing is never above the hip, and back swing with a chicken wing elbow, thus a very frequent twisted wrist in the release caused the ball always went left, high.
Once I go down to 14lbs, I overcame the ball line ) no longer go high to the left. I can play to board 10, 12, or even 6 for the breakpoint.
and surprisingly, as the ball is lighter, I grip softer, elbow is straighter, and swing is higher, thus the release also way less tense and eventually ball speed easily go up to 13 mph to 15 mph.
It is a wonderful transition about: "Less is more"
this is my feeling.
shared.