I replaced my ipro 1 recently, and I must say it works like a charm.
What I especially like about it is that I can have more confidence in measurements. It's robust, easy to clean and has automatic wavelength calibration, so you can trust that it measures the color in a right and repeatable way.
It's also more thermal stable, and has less problems with dark current noise, so it is better for display/projector calibration (and BTW the display/beamer holders are also improved)
The measurement ruler is also much better, and the measurement is more convenient, and faster and more accurate - I virtually have no errors while scanning.
Last but not least - as a graphic designer I really appreciate new design - the case with the gear looks like million dollars.
Of course I'm not sure if you will see the difference (do you alredy have i1profiler software), but I'm sure you'll see difference in comfort of use.
Personally I can see the difference in quality of display calibration, and didn't had enough time to make extensive test of quality of printer profiles for my iPF6350 yet (but so far so good).