If you are serious about mixing/recording, and especially if you have deadlines to meet - you'll definitely want something that has been proven stable and working with as little hiccups as possible. That's why using W8 over perfectly fine W7 SP1 is generally a rather bad idea at the moment.
First, its AE user base is pretty limited right now, as you can see if you look up for the W8 user experience on the net, so there is no much feedback.
Second, W8 hasn't gotten to the first service pack stage yet. And that is important, because by the time the SP1 is released most bugs are weeded out.
The fact that it is clear as day that Windows 8 is primarily written for tablets doesn't help it either.
Definitely no reason to rush decision.