OUCH! My vet did my Cairn terrier's spay & my little 2.5 lb Yorkie's neuter with the laser and didn't have to suture her OR him from the outside at all! They were both glued together and if you didn't know they'd had the surgery, you wouldn't have known at all.
There's just a tiny little line left that's about 2 - 3 inches long on her and not a mark at all on him.
Benefits of the laser are and have already been mentioned - it's quicker, easier for the vet, less mess/blood and therefore less trauma on the pet, less recovery time, less pain afterwards, less chance of uncontrolled bleeding after surgery
Laser surgery at my vet's office is $30 more than general. It's totally worth it!