Everyone seems to feel differently about this, but on balance I'd say that the more people you fly with, the more you learn. Different perspectives can be helpful sometimes. I'd recommend you book the new guy, and get on with it!
Be prepared for a harder time in the circuit than you have had so far: it's a hard thing to learn, and you and your instructor may well get frustrated with one another at some stage, whether you go with "Mr Popular" or the other guy!
Hope this helps,
Andy
