We've all been testing them for about a month now, I ride very loose trucks on an 8.38 and sometimes would get wheel bite riding old 149's.
The new ones are considerably higher than the older ones, Indys are 55mm high at the axle, the new 149's are 52.3mm at the axle. So that makes a big difference. Also, as a big fan of smith grinds, the lower set kingpin makes quite a difference as well. We also just wanted to clean up the look of the truck in general, the older 149 hangers were pretty meaty, almost as thick as a venture hanger. The new ones better match the lines of the 147, and the 151.
Everyone should feel free to ask me specific questions about them if you have any.