The range of hardware options makes reviewing the mobile OS more complex, and it makes choosing a device a much more confusing decision. Microsoft on its site--including the devices just announced this week. But, one is exclusive to Sprint, one to T-Mobile, one to Verizon, and four to AT&T (the remaining 3 don't have designated wireless carriers).

If I were a Verizon, T-Mobile, or Sprint customer, I guess my decision would be simple. I might not like it, but choosing would be simple because there only seems to be one choice. But, I am an AT&T customer, so I have four smartphones to pick from. I have options from LG, Samsung, and HTC. I can have a pure touchscreen, or a slide-out QWERTY keyboard. I can get a 3.5-inch, 4-inch, or 4.3-inch display.

With , I can either like it, or not like it, and it is what it is. But, with Windows Phone 7, I might hate it on one device (I am not a fan of the HTC Surround), and love it on another. I might have complaints about the clarity of the display that are a function of the hardware rather than the OS. I might have issues with the call quality, or the sound from the speakers when I am playing music.

The whole thing presents a dilemma, though--a double-edged sword. It is nice to have options rather than be forced into a one-size-fits-all box, but the flip-side is that there is no single "Windows Phone 7 experience".

As I go through the next 28 days working with Windows Phone 7, keep in mind that my experience is at least partially a function of the hardware I am using. I have the HTC HD7S now, and I think my Mango device will be a Samsung Focus when it gets here. But, preference of form factor is subjective, and your Windows Phone 7 mileage may vary depending on your hardware and wireless provider.