Im with Rob T. It depends what you are looking to get out of it. Most of the information they are presenting you can get from this website or through others online. Since they are targeting 11-15 YOs there most likely is going to be no one there "looking at" kids.
If they do the 5 tool evaluation right it would be like going through a showcase evaluation which may have some benefit for your son as he continues on. Nothing short term but when it comes time for a "real" showcase he will have gone through one.
If they provide you with the results of the "5 tool evaluation" it would give you an idea of where your son stands, but as they are not HS age yet (at least most of them) it won't really have much merit.
When my kid was 12 or 13 I might have gone to something like this. Now that we are in the middle of the process (he is a sophomore in HS) I look back and realize that these type of things are more for making money then exposing kids to college coaches.