What I'm saying about the "surprisingly disappointing" aspect of it is more down to the unfulfilled potential of the game. I expected that, considering the whole focus was the TT, we would have a more joined up experience in terms of the available bikes / classes / riders, a bit of a better thought out and detail structure around the whole excitement of taking part in the TT itself and also the handling characteristics of the bikes. Ok, I'm no biker sadly (the wife won't let me!), and I do struggle to get myself in the right spot to ride a bike game properly, but I've taken my own experiences with the title, added in the comments of folks who know about real bike racing and riding, compared to other bike games and come up with the conclusion the handling model still has a way to go until they can confidently claim they nailed it.
But again, its still promising, and TT 2 could well be the answer to those "disappointments".
I hope so, as it could potentially be a rather awesome game.