Pros: can't think of any, at least versus doing it yourself.
Cons: you'll get charged for stuff you can buy at a hardware store.
Welcome to the forum, and congrats on the thrux. I want one so bad. FYI, a lot of the thruxton and TBA are shared between the two. This is, however mainly geared specifically toward the america/speed master. That's not to say you shouldn't enjoy the forum or anything, just that you're definitely going to find more bike specific content at a more bike specific forum.