It has been a while since I purchased an iPod Touch. That device has been a quiet success alongside the iPhone. I don’t have any research to quote but I suspect it is also responsible for leading casual gamers away from Nintendo DS and the Sony PSP.
I use my iPod Touch for reading mostly, on the Kindle and iBooks apps. Its 3.5 inch screen provides me with a compelling reading experience for casual text-only books. That experience does not extend to reading more dense PDF documents with figures, magazines, or typical desktop screen size web pages. For that an iPad is without doubt an interesting device.
At 10 inches, the iPad is a little over my preferred size for
easy portability prolonged holding. I would prefer a 7 inch tablet that looks and feels like a scaled up iPod Touch, and includes a retina display. The iPad 2, sadly, looks and feels like a picture frame.
The iPod Touch with its dimensions
The iPad 2 for comparison