Equipman, No one can tell your son or family what the best choice is. No one else is living in your shoes and has the same priorities or desires for a college program.
JUCOs are like any other level of competition. There can be a wide range of difference between the top JUCO and the bottom JUCO. That's no different in DIII. Remember, IMO, Adrian is a TOP level DIII. They can certainly develop talent - absolutely no doubt as I've watched it first hand. Now, your top JUCOs are going to obviously be able to do that as well. However, to blanket statement that any level is better than another is just simply incorrect. There are many DII, DIII, NAIA and JUCO programs that can whip the pants off of many DIs, etc. Big range in talent and success between top DIs and bottom DIs... same for all the other levels.
You have to look at the history of a program, the location, the cost, the development, the discipline (whatever that means to you), the teammwork, the academics, the graduation rate, the weather, the transfer rate...... It's a lot to sort out and picking a college program is one of the most difficult things IMO. If I had to give one piece of advice, it would probably be to trust your heart to a certain extent. We didn't and have regretted it ever since. Our gut can sometime tell us as much as our brain!