I have used the Purist Burn-in disc for years. The old disc worked very well, but requires several days to do the job. The new disc is much faster, possibly cutting the time needed in half, or less.
On principle I would never disagree with Sean, but in this case I'm not sure his experience is valid since the PAD disc was running for a certain amount of time. Switching to the Ayre disc is piggy backing on what the PAD had already done. This is not to say that the Ayre disc is not good, I know nothing about it.
The convenience of the PAD disc is more than worth the cost. I would not be without the one my brother-in-law bought!