I spent much of my career working at HP on computers, Apple on computers and OS, and Windows on OS with Windows XP the last OS. Now I spend more time thinking about data centers, cloud, and mobile.
How much am I working on Mobile? I have three phones - AT&T iPhone 4S, Verizon Galaxy Nexus, AT&T Galaxy Note
As much as the PC is powerful, it is interesting what you develop when you make a mobile device your primary device with cloud infrastructure.
The above smartphones have dual core ARM processors, 32 GB of storage, 5-8 megapixel back, and 2-3megapixel front cameras. Each of the above have some advantages over the other. This is not about arguing what is best for an individual, but what works best for a usage scenario.
It is amazing how the kids want to play on these devices, and never ask to use my laptop.