I know you said target colleges will be attending both events. I'd ask the specific college coaches (your son is most interested in) which event is the "best fit" for your son to see what they say. Most likely the HC will be attending one event and the RC may be attending the other event for any particular college in question. Possibly one of those HC coaches has already seen your son and it may be beneficial for your son to be seen by the RC coach (for example) of the same school. Just a thought.