Use what feels right, there is too much noise about the various options.
If you can do the (short) learning curve Ubuntu (yes with Unity) can do pretty much any day to day task, productivity or otherwise.
I am not a Linux guru but just a small business admin so have to use all the OS's on a daily basis. I find Ubuntu the most natural desktop for ME others will disagree but I have been on Ubuntu for all my business functions for 8 months and have never failed to get the job done, office admin, accounts, graphics, CRM, you name it I do it all on my laptop.
I do boot back into win8 occasionally for a laugh but it really is so slow and painful to be productive I simply cannot use it.
OSX is a paragon of useability for non IT people but as has alredy been stated its not really geared to be "managed" in the traditional sense, that lovely veneer of ease of use becomes a ball and chain in a managed business environment.
So If you have got this far, take a punt on Ubuntu but really commit dont give up after a few days as its unfamiliar once you settle in you will wonder how you did without it, I do.....and yes I am still an MCP/MCSE.......