Routing USB2 signals
Does this offer advantages or is this even necessary? A theoretical advantage would be "less reflections", but is this real? 


It is an advantage. At USB 2.0 rates (480 Mb/s), it's probably not a big advantage, and it certainly isn't necessary. I've seen working designs up above 1 Gb/s using only 45-degree corners.

But it does look pretty, and it doesn't hurt anything.


  Note: I'm not asking about equal length paths, which these aren't.


I would rather see this design made with matched trace lengths and 45-degree corners than round corners but mismatched trace lengths.