Full disclosure, I work at a consulting firm as a network tech that sells Office 365. I certainly don't receive any bonuses for deploying their product, but thought that you should at least be aware that it's a product that does help put food on my table =)
So this is what I've seen with Office 365, specifically on Macs. It's a solid product. If you subscribe to it you will get the 2014 client upgrade when that is released. From my experience with the Enterprise side of things you may not get it day one (for the 2010 to 2013 transition Microsoft rolled out the service upgrades over the course of a few months for their clients, and it wasn't officially supported to download the 2013 version until your service upgrade was complete). The benefit here is you will get additional software on top of the Standard Word, Excel, PowerPoint and Outlook. And that upgrade when 2014 is released.
The downside is as soon as you cancel your subscription you won't have access to it, even after you've upgraded to 2014. Microsoft is committing to a more ambitious release cycle
for Office products, so the value may be there.
Regarding Outlook on Macs. For the most part it is excellent as long as you run it on a current system. My only client that has had an issue with it runs Office 2011 on an older Air (still a mechanical hard drive). She had over 20,000 emails in her Outlook spread over 5 accounts she had loaded into it.
I personally am thinking about setting up an Office 365 account to host my own e-mail. I am not looking to use it for my Office license, but that is based on my usage. I have office 365 at work, so I get to install it on my home PC through them. You are allowed to install the Office suite on up to 5 devices with your 365 subscription.