As far as Multi-AZ is concerned, it's a bit of a wash. A month ago when the east coast had its issues, Multi-AZ didn't do anything. Every time I need to reboot an instance, with failover it is down/inaccessible for the same amount of time as if I had just rebooted it plainly.

I'm sure there's scenarios where it's worked well for people, but I've never seen it happen.