Machines like this don't need the latest and greatest CPU. There were very few things that I do on my original air that tax its CPU. That's because I'm not editing video, etc on it. You basically have grown-up machine that you can do actual work on and it's not much bigger than an iPad.
Do I see a need to have both an ipad and an air? Probably not. If you have an ipad already, then chances are you would be better served with a larger laptop.
As far as the ethernet port. On a machine like this, it's not that important. I have a USB ethernet dongle and I've used it 2-3 times.