1. The Safari address bar momentarily drops down from the top and then back up again.
2. A loading modal appears for a few seconds and then disappears.
3. The page I'm currently on jumps to the top.
4. The new page slides in from the right and the old one slides out to the left.
Steps 1, 2 and 3 are extremely jarring and, in my opinion, totally unnecessary. (I mean unnecessary from user perspective; I understand that the behavior is probably difficult for the framework developers to control cross platform.) I guess there's an argument for #2, but does the user really need such an obnoxious cue that content is being loaded?
Anyhow, I'm a huge fan of the idea behind this and I'm really rooting for this framework to succeed. But I could not at this point in good conscience implement it for any projects I'm working on, sadly.