This is a highly controversial topic.
Personally, I'm completely against it. It is a convenient way out for those who find barking annoying. The root of the barking is not addressed. Dogs bark for good reasons, because they are bored, frustrated, fearful, etc. After debarking, they bark softer and you ignore it completely because it no longer bothers you, but the dogs are still bored, frustrated, fearful, etc. The dogs' general welfare are conveniently brushed under the carpet. Imagine yourself with laryngitis and having lost your voice, trying hard to communicate with someone else, but that person doesn't really hear you. It's horribly frustrating and depressing. Why would you want to put your dog through that? I would rather tackle the root of the problem and fix that instead. Where there's a will, there's a way. A humane and non-physical way to help barking dogs bark less. Because it's there, and easily accessible, we turn to it quickly to solve problems. We don't explore other options, we're not patient to try new solutions, to wait for these solutions to take effect. We want fast, easy, quick. We're dealing with a complex breathing, living, live animal, one with feelings, emotions, and complex behaviours which deserve to be treated respectfully and as what they are. We would never dream of sending our babies to get their voiceboxes surgically manipulated just because they cry and wail and deprive us of sleep, cause us stress and generally make us slightly mad, so I don't see why we would do that to dogs. They are not beneath us. They don't rank lower than humans.
It's very sad when I read reports of shelties and collies being the breeds most debarked. They were originally bred BY MAN to bark, the same darn specie that now puts them through painful procedures to stop the barking. I think it's crazy. We should take some responsibility in what the different breeds have become and not come up with convenient procedures to make what we prized them for before, go away.
So, yes, I'm against it. Wholeheartedly. I would go so far to say that I would move heaven and earth to resolve a barking problem for any dog I might own rather than debark him. Heck, might as well put it on record that if I ever debark a dog, I'd do the same procedure on myself.
On a related note, I see you are thinking of getting a sheltie. If barking bothers you, you might want to reconsider the breed.