Here is my summary of where the Vendors are at, at this time:
Windows: Can run a version of windows on just about anything. I can slap this hardware together with that hardware you have in your garage, and when we get it up and running, we should be able to slap Windows on it, though it probably won't be the latest iteration. Still, it will function, and even though I have been saying this for years, I still can say it to this day. It is not as smooth as Apple, but it is a free'er experience, at least from a hardware perspective. Most people use some form of it, and most applications are designed for it. Because of this, it plays nice with the rest of the world. Microsoft is mostly trying to play catch up now, but they are stepping up to the plate a bit late imo. They are also piddling off a lot of their base by forcing major UI changes designed for touch on them, even though the vast majority of their base are not using touch computers. This is back-firing on them in a lot of ways, and they are now back peddling to undo some of the damage.
Apple: Closed, mostly secure environment, which is both a pro and a con. Attention was put into making the OS smooth, pretty to look at, and easy to use which has won them a very loyal fan base. Apps load, pop up and go away with pizazz and style, and it is generally easier to code better looking applications in this environment. Still, you are stuck paying more money than you should for Apple hardware, and you are locked into it once you buy it. Your 200 dollar iPhone cannot expand past its measly 16gb of storage, and you will have to buy a custom cable to charge it. Jailbreaking will improve your experience immensely, and there is no shortage of advanced features available should you take this course.
Android: Android has a lot of promise, but falls short when it comes to security. They are not above copying what works well with other vendors, and this is a big benefit for them. If another company does something cool, they copy it, though they also are good at innovating and doing it in their own way. What you get is a very open and enjoyable experience in a more or less wide open environment that attempts to take the best of all worlds and implement it into one. The source code is readily available to be downloaded and tweaked, and there is a rich community online to learn from. Security is the failing. That, and the fact that there is no note-able desktop OS. If Android could run on Desktops, Windows would be in grave danger.
Blackberry: Very secure, corporate driven environment that was once the biggest player in the market, but is now very much on the verge of collapse. Their CEO is living in denial, and should hire someone else to speak for him when they release something new to the public. There is still much to like here, but they too are definitely playing catch up with both IPhone and Android, ever since the iPhone was released in 07'. The Z10 does have promise, but I personally would have rather seen a 9820 that runs BB 10.