Had one that did and one that went straight to a -3. I Don't know that I noticed a difference or if it would have made much.
Let me say this.... and this is strickly my OPINION IT IS NOT BASED ON SOLID FACTS,... but several years ago the legal drop for High School bats was a -5 then it changed to this -3 and BESR Certified. First they had to have a sticker then they realized you could take the sticker off and put it on another bat that maybe WASN'T CERTIFIED so the embeded painted on BESR Stamp was invented. Well this left a lot of -5's on the selves at a lot of Sporting Goods Stores... and I am sure in surplus, so what do we do with them???
We'll call 'em TRANSITION BAIT I mean BAT or was it just a gimick to sale more bats???
What ever it was they are here and some use them and some don't. Let your son decide, if he feels more confident then by all means get him a -5 or just continue with what you have. I have a -5/31" Louisville Slugger Air Attack2 that is like brand new I will give you. Remember though that by the time they reach the 9th grade they will have to use a -3 and with bats being as expensive as they are and lasting about a season and 1/2 or so choosing the right one can be another hair pulling
experience... I always wait until the new bats come out and buy the last years model for about half the cost.... hey it's a new bat....