I have had a temporary one for just under half a year. While I wasn't looking forward to it, I was actually in many ways a little disappointed when the reversal happened.
For me, pros were significant. No more straining to go, very quick when I had to empty the bag, no more worrying about getting to washrooms. No more pain.
Cons: mine was done on an emergency basis, so it was not well situated for long term use. It was just above the belt line, so I had to get used to track pants. Hockey and golf with its location were both no-gos. I know there are special restraints that can be had for those with more active life styles.
My stoma was before I started remicade. It took about a year to get my dosing correct (it included adding imuran), but it definitely works. I was up to a surgery every two years with the occasional dilatation thrown in before, and I have not had to go back for anything other than a very minor stretch that was done during a follow up colonoscopy.
I would imagine that he would like feel quite self-conscious about the bag. Kind of difficult to hide it at a day on the beach. However, it could also help him focus more on relationships that are more genuine. That is actually a pretty big upside in the current world. Tough to sell that one though. As a 20 year old, I let my crohn's run my social life. It is about the only regret that I genuinely have during my time with this ever-so wonderful disease.