I am not giving any identifying details about these 2 unis or the course because I really want you to focus on just this one aspect and how much of a deal breaker it would be for you/your DC.
Uni A and Uni B have given comparable offers for DS to study essentially the same subject. There is very little to choose between them. DS thinks he would slightly prefer the course content at Uni A. In other ways Uni B would be more convenient in terms of travel and accommodation costs, etc. and they offer some free equipment that would be useful. I would respect his decision to choose Uni A because of the course content despite those factors, but...
This is the biggie: Both courses involve a third year work placement (officially optional, but it sounds as if everyone normally does it and there are definite advantages).
At Uni A, this placement is not paid. I assume they just get a student loan like in other years.
At Uni B, the placement is paid (reasonably well by the sound of it).
Of course we want him to do a course he will love but being paid would obviously be a big advantage, especially as we have another DC possibly going to uni a year after him, and it could be an expensive few years.
In our place, would you be trying to persuade him that Uni B would be the better option? He doesn't hate the course there, just thinks Uni A might be "even better", and time is running out to make the decision...