Please note that v9 WIP is not suitable for stable use at this point in time. Things may be broken, leading to crashes, and potentially to loss of data, and v9 WIP will change unannounced from one week to the next.
A better option IMHO is to use v9 in projects if there is a new feature like the re-implemented Patch command and the many other improvements, and copy the results back into v8. If both are open at the same time pasting from v9 into v8 is seamless.
Aside from using it in projects like outlined above, you are more than welcome to take v9 WIP for a spin when there is no pressure, and report back your findings: what works, what is broken, how can things be improved. Like @bobmcneel said, without feedback from users, we’re not going to get where we need to be.