Thanks to the thread starter for the detailed summary on the Nexus 10!!!
When the Nexus was announced, I was impressed by the specs, and tried to order one on release day, but it was already sold out. A couple of days later, I got a 4th generation iPad in a local store instead. For my primary usage case (reading and commenting PDF documents, webmail, as well as interactive queries to an online database) the screen 4:3 format of the iPad used in portrait mode is perfect. The Nexus 10 screen in portrait is about 15mm taller, but also 15mm narrower, thus less optimal for reading PDF documents (with their fixed linebreaks).
The Nexus 10 16:10 screen ratio, though, seems to be better adapted for viewing widescreen movies. Still, with the iPad I could simply do a restore from the iPhone backup, and had all my frequently used Apps and settings readily available (of course, in the meantime I have replaced some of the non-universal Apps by their iPad equivalent). I'm also quite impressed by the screen quality, handling, battery life, overall design and speed of the 4th gen iPad. The only things missing in the iPad Wifi is GPS, and an easy way for wireless transfer any kind of file or document with any other mobile device (it would be nice if one could amend the bluetooth stack of iOS devices).