I'm a bit late looking at this thread, but I've had experience with these events both through by sons' baseball travels, and many other players I've tutored over the past six years (I try to persoanlly attend both events every year). The Top 100 and Select Fest represent some of the very best exposure that money can buy in my opinion, great "bang for the buck" value in either case, two of the best early summer exposure opportunities on the East Coast. As indicated, they are invite-only events so that helps to ensure the overall quality of talent in attendance which, in turn, has attracted a bevy of college coaches (estimated 70-80 schools at Top 100, more usually at Select Fest). In more recent years, I've seen a broader variety of schools on hand including more DII and DIII programs which suggests that some of these recruiters are jumping on the bandwagon earlier in the process than in the past in order to begin targeting players sooner than later.
If you earn an invitation to either of these events, I strongly suggest you consider attending (unless you have already signficantly narrowed your college possibilities, and will primarily focus on a select target list of college camps that truly reflect your Recruiting DNA, i.e, your student-athlete profile)...and participate in both opportunities if possible, a ton of college exposure possible in a very short period of time especially to kickoff the summer exposure circuit. Not an easy invite to earn in either instance, many players don't have access to these opportunities so, if you are invited, I think you would be hard-pressed to find better early season, individual exposure events in the Northeast/MidAtlantic regions. Another potentially excellent showcase option in June here in my neck of the woods is the Perfect Game Sunshine Northeast, historically a very strong event as well!