Hobo didn't seem to be in any pain, but he was also on a pain medication. Our vet feels like it's really important because if they're in pain, they don't eat, if they don't eat, they get sick, they don't heal well, etc. He also insists on antibiotics to try and cut back on abscesses in the area.
The first night home he was really groggy and almost drunken acting. The next morning I woke up and he was rumblestrutting at the girls through his quarantine cage bars.
I don't know if every vet does it differently, but Hobo didn't have sutures. They used some type of surgical glue. The incision had nearly completely healed after about 10 days, but he also had to have an abscess removed, and then part of his testicle stump was poking out of the incision, so we had to take him back in for that. He seems to be having a problem with the particular type of suture he used, since he's switched since then, so I don't know how normal those types of reactions are.
It was very stressful to me, but I'd also been dealing with Hobo's sickness for about two months at that point. He had a testicular tumor that we didn't find until it got quite large (since I'm not in the habit of checking for lumps in his testicles), and had problems with stasis, anorexia, and pain while peeing. It was a relief, but I kept thinking that such a 'quick' fix was too good to be true.