Testing EV and Win8 / Office 2013

Greetings all,

We've been running EV for email for about two years or so now but are currently on v9.x and I've been asked to start looking at Win8 / Office 2013 for next year. I've gone through the compatibilty charts and seen that Win8 is EV v10 only so I have a few questions. 

Firstly what's the upgrade process like from v9 to v10? Any gotcha's to look out from experience?

Also as an idea totally out of left field - would Win8 work with EV v9 if the client used the v10 of the Outlook plugin?

Thanks in advance etc.