My son who was a junior last year attended the top 96...it's a great event. that being said there were about 4 or 5 underclassmen (freshman/sophs') there and they were clearly out of place at the event. I wouldn't take a kid unless he was a very good sophamore. That's just my advice and recomendation.
A benefit of the TPX clinic is that the kids work with college coaches. It is not "just" a showcase. I think it might be useful if your kid is interested in attending one of the colleges whose coach worked at the clinic. A drawback is that it costs $$$$ to bring in the college coaches.
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