I have 1 B17 and 2 C17's. all three are good for at least a 100 miles before I start thinking about them. On the C17's one is the special which has the organic cotton top. I actually think that one is a little softer but not enough to really make a difference. I think it looks better. I wish they were lighter weight but 80 miles into a long ride I doubt the extra 3 or 4 ounces is making any difference.I have moved the B17 to my barely gets ridden bike but it sure feels good when I jump on it.