I'm curious as to why they think cloning would degrade performance. I don't see a big difference between that and starting with a clean slate.
In my opinion it would be an advantage to clone your existing drive. From my understanding this drive will learn the most used reads, in a cloning process you will just write a lot of data to the drive, nothing will be learned at that point. Once you boot up it will start learning as you will read from the drive.
Will get mine in a couple of days, I will definitely clone my old one.
Something to do with SSD/HD alignment, I think. Cloning might transfer a misalignment while a straight install will have the alignment properly set, or something like that. And that misalignment will cause performance issues. Google it if you're really interested, as I'm not too sure on the specifics myself. I'm getting an SSD for my Mac soon and I'll be breaking from my tradition of cloning.