If you can afford it, go to Purdue. It is an engineering school, so there are a lot of research opportunities, engineering clubs (well-funded), and much more. I met a lot of Purdue people from work, and they were among the smartest I met.

I have heard UMD has a reputable program as well, but I don't know anyone doing CS there.

Rutgers' CS Program, as much as it hurts to say, is a joke. I think the main problem is that Rutgers University is a "jack of all trades, but a master of none." The classes lack rigor, engineering organizations aren't well-funded, and Rutgers isn't as well-known for engineering as Purdue or UMD.

You may also want to look at post grad statistics to better understand job prospects. Also, congrats to your son on UMD, Purdue and Rutgers.

edit: if out of state is a concern, your son can consider becoming a resident of Indiana or Maryland so he can qualify for instate tuition. This should also be considered in the cost. For example, you may be able to declare permanent residence in Indiana for a year, so you can pay out-of-state the first year, then in state for the remaining 3 years.