Sorry for the late reply to this piece, but I recently joined.
I agree the piece is played too quickly. I studied this with George Sakellariou, who plays this perfectly (as all his pieces). It is a great thumb study. It works on the independence of the thumb and the staccato technique. It's a real workout if you do as classykid suggests and play it with i,a and m,a. This piece sounds good at almost any tempo and is one of the best right hand exercises you will find.
In regards to the piece, Coste did a great job going through all the harmonies so seamlessly. He demonstrate himself to be a very knowledgeable composer with this piece.
In regards to Llobet, recording technology was not very advanced at this stage, so the mic may have brought out the middle notes too loudly. The technology may have sped up the recording also. Who knows, maybe he was just showing off. He certainly had the ability to do so.
Anyway, I hope no one avoids this piece due to Llobet's tempo. It's fun and useful.