I purchased an extended warranty, but mine was more due to the number of miles I was driving in a year. Both warranties were gone by year 3. On our new Mazda we did purchase the warranty as well. I like them because I don't like the cost of emergency service.
You mention the clutch??? I have 112,000 on the original clutch of my car, I'd have to disagree with it being a weak point. Now if I would have know I could have fried it and had it replaced at some point under warranty, that might have been a different story. I don't drive the car that hard (my wife would disagree).
It comes down to personal needs, really. You're going to get opinions from people that never needed them and think they are a waste of $ and you'll hear from people that may have saved > 2 or 3k because of some failure.