) of the player and any prior experience the player's parents may have with a draft situation (e.g., already had one son drafted). Players that are expected to go after the 10th round may not feel the need to consult with an advisor, because they may believe that the advisor can't offer them much assistance. Other players who are expected to go in the 4th thru 10th rounds might well benefit from an advisor to help not just with suggestions in dealing with negotiations, but with understanding the whole process and acting as a PR man/woman for the player ... to help improve their visibility if you will ... during their "draft season". And as far as top prospects ... well, they probably could use an advisor to help them through the rough spots and all the stress that goes with the attention and contacts from the scouts ... that wasn't something our son had to worry about at all 
On a personal level, our son found it helpful to have an advisor, especially in the last month before the draft as he sustained a minor muscle strain that kept him from his last 3 or 4 starts. I won't say that he panicked, but I do know that it helped all of us, including fiance, to meet with his advisor to discuss the situation and what he should do, what he was willing to negotiate bonus-wise if he was drafted lower than the 10th round.
As far as Boras ... I guess if a player is so good that Boras et al would even consider working with him .... well, he has a different set of concerns altogether than other players. Our son's advisor-now-agent has represented some high draft picks in the past couple of years and was advising a local star until the rug was pulled out from under him and another high profile advisor talked with the father of the player, and the next thing the first advisor knew was he was no longer in the mix. It was interesting, too, as the player really liked his former advisor but dad made the decision for him ...
Anyway, these thoughts are based on our son's experience and that of some of his former college teammates who were drafted in the past 3 years.