Not Quite a Real-World Analysis
Having used or currently using a Surface Pro 2, a Surface Pro 3, an iPad Air 2, an iPad Mini, a Galaxy Tab 2, and a Dell Venue 8 Pro (along with looking at many other tablet offerings), I feel that simply reading a vendor's spec sheet doesn't give the whole story.
In the case of a Surface Pro 3, it's excellent graphics, ability to use bluetooth devices (e.g. mouse and keyboard), and USB adaptor make it the first choice for most Windows-centric shops. However, cranking up the processor (I have the I7 in mine) reduces battery life to the point where some laptops outlast it. Another concern is Microsoft's apparent backpedalling of a touch interface with Windows 10. With Win 8.1 there was at least a reason to consider a touch interface. Now, not so much. The MS keyboard is a non-starter for pretty much anyone that relies on a keyboard for much of their work. The reason? No Insert key (which also means no type-over key), something that at least I find I need to use every day (and trying to use the . The hidden gem? OneNote. Definitely one of MS's best software offerings to date.
Apple has long been the "master" of the touch interface. Give a 3-year-old an iPad and they are able figure out how to get around in no time. I've never seen the same level of aptitude gained so quickly on a Windows device. However, their drawback has always been the touch interface. For people with bad circulation (cold fingers), people that work with their hands (mechanics, cooks, or anyone else that ends up with "stuff" on their fingers), and - on occasion, people that have large hands (moreso an issue on the iPad Mini) the touch interface is not a viable solution. Apple's finally acknowledging that a stylus (pencil) may be beneficial is a step in the right direction. To those that say an Apple device cannot be part of a network, they're simply wrong. My iPad has full access to my company's network. True, it cannot "see" shared Window's drives, but that's solved with applications like OneDrive (another good MS product). The ability to do split-screen (which seems to only work with certain apps so far) is something that was way overdue.
Dell's Venue 8 Pro (not mentioned in the article) is actually a dark horse in this race; a 32-bit processor and a battery that lasts all day running Windows 8.1 or 10. The 8 Pro is a phenomenal value for non-business use (if you consider the cost of both a Windows OS and Office Home & Student license it's almost like getting the hardware for free). It can also take a 128GB MicroSD card (although you cannot map OneDrive to it). Dell also routinely runs bundled sales making the deal even better. The 10 Pro boasts a larger screen (and a 64-bit processor), but not a bundled Office license (which may be better for many businesses). I have not tried out a 10 Pro, but I suspect you'll find it's numbers (and battery time) comparable to a Surface Pro 3.
Going with any Android device really depends on a company's environment. Like an iPad, they don't seemlessly integrate into a Windows world. However, OneDrive is also available (making drive mapping a non-issue) and for the most part network connectivity is a non-issue (not sure if Cisco ever ported over an "official" version of their AnyConnect product for VPN access). Any one of the Android devices mentioned (as well as the 10" version of the Dell 7000 series) could be a viable contender, - especially if the company is using Google Docs.
In the end my company's choice was the Surface Pro 3. Why? Because we wanted to standardize on a 64-bit version of Windows, take advantage of Active Directory, and (probably the biggest decision factor) have business relationships with both Microsoft and HP (which pretty much took Dell out of the picture - much to my chagrin). That, and the head of our hardware group has a strong dislike for all things Apple.
Do I like my Surface Pro 3? Absolutely! Do I like my iPads? Most definitely! Do I like my Venue 8 Pro? Certainly! Which do I recommend? It all depends. In today's world there is no longer one clear solution.