I have an ipad 1 on 4.2.1 ios. Recently bought an ipad mini. Even more recently got an ipad 4 which I haven't unboxed.
Although the ipad mini is great for portability, I still prefer my ipad 1 over it. The ipad 1 is only slightly slower in loading flipboard over the ipad mini. I haven't updated flipboard on the ipad 1 and it works just fine, imho. I play my favorite game, Rapio on the ipad 1 everyday and images definitely looks better on the bigger screen compare to the mini. Can't emphasize this enough as graphics just lose impact and beauty on the smaller screen. The 32Gb on my ipad 1 is down to only 2Gb free space and I've stopped downloading apps a long time ago. I've only tried out 20% of the apps and stuff I have on the ipad 1 due to the lack of time to check them out as I'm either on flipboard or Rapio in my free time. Still love my classic dinosaur and will not part with it even though battery last six hours now compared to the initial ten. Just secured 600 free Marvel comics throught Comixology a few days ago, and the new ipad 4 would be perfect to house them. Ahhh, life is great...