Please don't do this regularly, though. The reply option is missing on posts for a time to attempt to reduce bad behavior, and even though it's a bit leaky through the permalink page, using that a whole lot may prompt pg to close the leak. In general, I only use it when I will not be able to reply for hours if I wait 5-10 minutes (about to start a drive, or be in meetings, or whatever).
If you're not using it for mischief, I don't personally see the harm in it - the "missing" link is still fulfilling its purpose of discouraging "evil" impulses by making it just that little bit harder to carry them out.
People were arguing with each other and creating deeply nested comments, ignoring all other discussion. The delay exists to give them a chance to cool down and reconsider the wisdom of arguing.
The site will permit one to reply after a bit of time. If it is delaying you, it's probably best to use that time to improve your comment by citing sources or editing it to be clearer and more concise, rather than using the cheat to post straightaway.
