Blackberry w/ Office 365? Easy or hassle? BES needed? Is it as simple as activesync?

I did see that article too.  

He'd be buying a new device so the simpler Blackberry 10 would be his selection.

So, "BlackBerry 10 smartphones can connect to Exchange Online directly using Microsoft Exchange ActiveSync."

Is this even needed: "blackberry cloud services"
http://us.blackberry.com/enterprise/products/cloud-services/overview.html

I really don't want to complicate our new office 365, requiring us to learn a whole different interface/process just to support one phone.

Give me reasons I can use to say no !!

Thanks,
Mike

Is there any one-user appropriate way to let him have a blackberry?  

I'd like to say something like: "BBCS is entirely too complicated; if we don't get BBCS, your blackberry would not sync mail but only have a copy (for example, if that's true).

Is there anything provided strictly as part of the office 365 platform that supports syncing mail to a blackberry without running new layers of blackberry software?

And lastly, would having one blackberry reduce the reliability of mail for the entire enterprise, or just that user?

Thanks,
Mike

So sorry, I didn't realize this was still open!

Thanks for the answer!

-Mike