Yes. Early decision essentially puts all the eggs in one basket. If you think you have a reasonable chance of getting in (and I mean be BRUTALLY honest with yourself) or have some family reason for wanting to go to a certain school (spouse, children, etc), then ED is a good way to make sure you end up somewhere. ED is a gamble for a school, so its really tough to get in that way, but if you do, more power to you.
Also, from what I understand and have been told many times is that you can only apply to that one school. After Oct. 15th, you can apply to others if you aren't accepted. If you ARE accepted, you are committed to that school and can't apply to any others after that. Its nice to know where you'll be going next year, but its a gamble if you don't get in because now you'll be rather late in the process.