Advisors........the good ones are really good and the bad ones......well, they wreck draft status, potential deals and lend little guidance to college-bound kids who need that time to develop vs being thrust into adulting with grown men. We had both, fortunately, and in my book our first experience was terrible as son was in HS while the latter and best experience was in college and exceptional. I had a friend call me about the MLB draft after son was drafted and his son was up that year....he asked what we did to land with an agent and how it happened. As i talked to him i realized that i couldn't really offer him much info. They found my son. Frankly, i hadn't thought that far ahead and shame on me for it. Who knows where he would be and with what resources? Ask around, talk to teammates who have the top tier advisors or others and network....there are a few that lead the pack and many who are solid and do a great job advocating for the players. I think everybody can detect the slick ones and if you can't or want to ask them a few questions; Ask who they represent now and where they are projected to be in the upcoming draft, who they've previously represented, what slot they went and where are they are now in the MLB system, along with how many 1st-5th round guys they have in their stable now? While money isn't everything as TPM mentioned and getting to arbitration is HUGE, you should be able to separate the wheat from the chaff pretty quick.
Some we know of that had clients affiliated with son via HS, Travel or College ball are:
CAA
Ballengee
Boras Corp
Jet
ACES Inc