TPX in Dallas event had 10 colleges present. Others I have seen had 20 or more listed. Well run event.
Keep in mind it is a evaluation and grading verses a showcase like PG. Do you get colleges to contact you afterwards, most definately if they are truly interested. My sons name was passed to a 'private' showcase game to play in front of some top line schools in a double header. Only 10 guys from our TPX event were on the email DL for the event and there will be about 40 in attendance at this game.
Any exposure to colleges is always good