In reply to Rob Exile Ward:
I'm a bit of a 'PyB regular', having done probably more than a dozen courses there in the last couple of years.
There are 2 main reasons I keep going back:
1. It's super convenient: I don't have a car and hiring one for a weekend works out roughly the same as a 2-day course at PyB because of the dreaded young drivers surcharge. I also don't have a regular climbing partner and find trusting complete strangers enough to go climbing with quite hard, so I prefer doing weekend courses and not have to worry about finding a partner, driving from London and so on. PyB have a shuttle service from Llandudno Junction train station, so it's very accessible: 3 hour train ride from London, get picked up from the station, have a weekend of worry-free climbing, get dropped back to the station, 3 hour train ride back to London.
2. Every instructor I've worked with has been brilliant. They all know their stuff and are super friendly. I've never had a bad experience there and I've probably worked with over 15 of their instructors over the time.
As I run out of courses to do, I will have to eventually get a car and find a regular climbing partner, but for now this works for me.
Now, back to your question: although I haven't done the 2 day leading course, I have recommended it to a friend, and he was very happy with it.
Personally I did the 5 day leading course instead, and, if your son has the time and you're willing to increase your budget for it, I would recommend that he does that one instead, simply because you get a lot more time on lead, learning how to judge your gear, build belays etc.
Either way, I'm sure he'll have a great time and learn loads.
TL;DR : PyB is great, go for it!