After twiddling around with the AIR UI, I found a few tiny bits that bothered me and as I continued using the AIR UI, they only bothered me more. The bits that bothered me are actually basic parts of the FLASH UI but they never bothered me there.
The problem is the way UI items are styled. While I can live with, and certainly appreciate, custom icons for maximising, minimising and hiding windows, I have a hard time dealing with the custom scrollbars, the dropdownboxes that simply look and feel different ...
Somehow, it never bothered me while running in a browser because my mind was set on "it's Flash, it's in a browser, it's a plug-in, it's not running on your O/S so it doesn't have to behave like it's running on your O/S".
But now, we have AIR and, from a user POV, AIR is at least making it look like the application is running on my O/S. It's a detached window, floating around on my desktop and so I expect it to look more like it belongs on my desktop and not in a browser.
The whole UI thing is also a lot less bothersome on the MacBook. On the Wintop, it seems ... out of place. It makes all AIR applications look like a gadget instead of an application. It's okay for an application like Thwirl which I consider to be a gadget, but it may actually make life just a little more difficult for full-blown AIR applications to make it onto the commercial market.