As others have pointed out, it completely depends on what floats your boat. I have three tablets - the iPad4, the Nexus10 and the Surface 2 (which was preceded by the Surface RT). The thing is that I use the tablets for different things. Thus, for example, I use the iPad4 as a dedicated e-reader and only occasionally to use a banking app. I use the Nexus 10 only for watching movies and I use the Surface 2 for everything else - browsing, Office related work. The Surface has effectively replaced my laptop (though I do have a Win 8 desktop machine, which is a 2-monitor set up that I find myself using less and less).
Arguably, I can probably cut down on one tablet. If I was to do so tomorrow, it would be the Nexus 10. This is because I can use the Surface 2 to watch movies. The 1080p screen is very good - at least for my purposes. But I would hesitate to get rid of the iPad. Why? Simply because of (1) the aspect ratio, which to me is the best suited for reading e-books - various formats; and (2) some of the best reading apps that I have found are in the iOS store (personally, I use PDF Expert for working with PDFs, which I find myself doing most of the time and iBooks for ePUBs).
But if I could find a Win RT device which has a 4:3 aspect ratio, then I would seriously consider also dropping the iPad. But I must have a good app (in the Windows store) that can handle PDFs. ePUBs is not so much of a problem.
The point that I am making, therefore, is simply this: It completely depends on what you need to get done and what you want to get done. I have found when buying technology, while there is a natural tendency to buy stuff that one thinks one likes, it is probably better to buy the stuff that one can use to satisfy a need. Less regrets that way.