Single Vendor
Some of the problems that I encountered in the two years using the Nexus One, and these were more specific to the hardware rather than the software, made me decide to switch to an iPhone and also to Apple as my "preferred vendor". I won't elaborate on the issues here but just to say that this isn't a swipe at Android or the handset I was using, the Google Nexus One.
Yes I believe Android is more open, and I'm using that term loosely. By "open" I'm talking about having less restrictions on what I can do from both a hardware and software perspective and not who owns the source code. For now I'm happy to work within the confines of the Apple ecosystem. Everything just works when you go with the same vendor, vertical integration if I may. For example I'm now using iWork instead of Google Docs, iTunes instead of Google Music (the older non-geo restricted version of the player), and, iPhoto over Picasa.
My content is synced to the plethora of devices that I own so my content is accessible as much as possible, but only on Apple devices. Dropbox also fills some of this void.
Once you start crossing borders you run into small niggling issues, e.g. I wasn't able to sync my contacts to both iCloud and Google. Little pestering issues like this help make the decision to a single vendor stack .
I'm hoping that in the end that this will fare out well and I haven't locked myself into some corner. It also means that I need to keep up to date with the Apple products to ensure my content isn't locked out by later versions.