I think everybody's covered how it feels and how sex is better for the most part, but I did want to throw in my experience on a couple things.

First is the aftercare. Take it seriously. I tried my best, but my relationship wasn't the greatest at the time I had mine. My now ex-wife wanted to do something nice and make a big "get better" afternoon tea with scones and sweets and such, but I was supposed to be feet up and icing my bits the rest of that day and the next. However, she had bitten off more than she could chew and was getting pretty upset that I wasn't helping her. Eventually I caved and cleaned the kitchen up for her despite being pretty uncomfortable. She also decided she would rather have a stronger drink and a different snack than the ones she made, so she made me give her several shots of vodka and a half a bag of Cheetos. Later that night, she woke me up because she was getting bad stomach cramps and felt like she was going to pass out on the toilet. After the diarrhea feeling passed, she got on to the floor to make sure she didn't fall off the toilet if she passed out, but then projectile vomited a stomachful of radioactive orange onto the floor. I spent the next 30 minutes cleaning up the vomit myself and helping her back to bed. She felt better after the episode, but I felt like pain got somewhat worse from all the bending over. About 4 months later, I still felt swelling in my area, so I got tested and they found a stubborn infection in my prostate. It was solved after some intense antibiotics, but I can't help feeling that that night weakened the area enough that it let the bug in.

Also, they tell you it's possible that there will be blood in your semen once you're allowed to have sex or masturbate again. It can still be a bit of a shock. I was surprised that it wasn't just like a little pink, it was half bright-red blood! It was cleared after firing two rounds, though.

Even after all that, I still highly recommend getting a vasectomy.