People, please. Seeing Sagan close the distance on Cavendish in the last 150 meters does not mean Sagan was the faster sprinter. It means Cavendish slowed down and raised his hands in celebration. Look at it again, Cav does not finish full speed because he already had the stage won by well over a bike length. Stops pedaling and raises his arms to yell in delight. Goss had given up and also stopped pedaling, while the only one of those three that was still going all out was Sagan. So of course he was going faster at the very end. It certainly does not mean he was the fastest guy out there. Cav's last two sprints, both from 350+ meters out, have been the most impressive I have ever seen him do, and I've been watching him since he broke out. I do not believe anyone is capable of that level of sustained speed alone in the wind for that length of time. I didn't even think he was capable of it.
At any rate 23 stage victories = greatest sprinter in Tour history. Sagan definitely has the potential to get that far and even further, but at the same time, for all his sprint speed, he is more than just a pure sprinter since he wins in breakaways and rolling stages. I imagine he will be dominating spring classics as soon as next year. To say that Cav is the best sprinter there is, and probably the best there has ever been, is in no way to diminish Sagan's talent. I rather like both of them. Sagan is the more versatile rider earlier in his career, can win a wider range of races and stage types. Because of this, he will probably develop into a classics rider and rolling stage winner rather than a pure sprinter.