jimdandy welcome to the site and please understand you've come to a wonderful place with tons of baseball knowledge from all kinds of levels and experiences.
That's a good question you got and you are going to get a ton of different responses from everyone. There are pros and cons for each side of playing fall ball or going to camps. I guess before I can give my advice I need to ask - how interest has your son seen from college coaches so far?
There's two ways to look at it - cast a huge net and hope for a good catch or get a smaller net and try to hook a specific catch. What I mean is that IMO if you go the fall ball route you need to make sure it's the right team and situation where you WILL be playing in front of college coaches. I don't know the level of talent your son has and stats won't help me or anybody else on here to know how good he is so you have to make sure he plays on a team that is of his skill level. By doing this you're casting the big net in hoping he's seen by the right college coach at the right time. Then the recruiting process will start and lead to a scholarship. If he's not on the right team / situation where he's playing and no coaches are there OR he's sitting the bench then he's wasting his time. When choosing a fall ball team make sure you know what you're getting into.
The smaller net is that your son knows, or at least has a good idea, of what schools he wants to attend. Make a list of 5, 10, 15 or however many schools he wants to attend and fix a schedule to attend as many camps and showcases that this list of schools will have or attend. This is good because you're being seen by the people you want to be seen by. Don't leave it up to chance either. Make contact before the camps / showcases explaining his interest, introduce himself to coaches before camps / showcases and then perform. Now the recruiting process is hopefully started now.
The truly best option is to do both - get on a good team and attend camps of schools want to attend. This will cost some money to make sure you plan it out very well. There's not a lot of money in college baseball scholarships so make sure the grades are strong to get academic money to finish what baseball doesn't provide.
Hope that helps.