You have to take into account the larger memory footprint of iPad apps as well. No doubt they could have run the base OS without much trouble but there wouldn't

You have to take into account the larger memory footprint of iPad apps as well. No doubt they could have run the base OS without much trouble but there wouldn't be a lot of memory left over for apps. So an iPad 1 with iOS5 and enough free RAM to run apps is better than an iPad 1 with iOS6 that can't do much more than run the OS. Apple learned their lesson from the iPhone4/3G thing.