2 things would be a deal breaker for me on that bike. The newer 600's may not be tuneable without special software not available to the public. Something about the interface supplied currently, that can be tuned, vs. a new interface that can't.
And 2nd, if it has steel gears, it's pretty noisy. There are plastic available, but they would be extra cost, and then there's the install.
The 600 has come up in the Frey bike forum if I remember right. You might look into more info regarding that motor there.