On the face of it Android seems the best choice. In terms of value and choice Android does beat its competitors - the OEM/platform model means that prices drop faster on Androids, and you could fit out your entire office with Androids, or offer each staff member their choice of Samsung, HTC, LG, Huawei and more. Plus, if your office primarily runs on Google applications, Android will work perfectly with your cloud provider.
One challenge for Android is security due to its very open nature. With an office full of Google phones it is all-but impossible to control what information is accessible outside the building. And with a plethora of Android OSes in the wild, you have no way of making sure the you'll be on the same platform as your colleagues.
There are some great Android options out there, the Samsung Galaxy S7 and the Samsung Galaxy S7 edge offer great displays, compatibility with all USB powered peripherals and can be upgraded to a bigger storage model by just adding an additional SD card. Android devices are customisable, and compatible with an array of Google tools such as Google Docs, Analytics and Google Drive.
Compared to the iPhone, the Samsung Galaxy S7 does offer longer battery life and the Samsung Galaxy S7 edge provides a bigger screen to rival iPhone 7 plus users, this also means that there is more room for a bigger battery, perfect for nomad business users.
29th March 2017 marked the release of the Samsung Galaxy S8, which you can pick up for a pricey £689, which is more slightly more than the latest iPhone with similar specs. Apple is rumoured to be releasing a new iPhone this year so the difference between the latest iPhone and Samsung offering should grow, depending on what Apple release.
The Galaxy S8 specs are pretty impressive, although not particularly different from that of the S7. It offers a great screen, 4GB of RAM and comes with 64GB of storage as standard, not to mention Bixby, Samsung's answer to Siri or Google Assistant.
You can pre-order the Samsung Galaxy S8 now, with its official release coming on the 28 April 2017. See here for the hands-on review.
Alternatively, if you want a cheaper, but still solid phone, the Huawei P10 and LG G6 are excellent options (although the G6 UK release date is still to be confirmed).