Samsung Galaxy Note 10.1 (32GB)

Pros: Wacom pen (active digitizer, not "stylus")
MicroSD card slot
USB Host
Great screen - accurate, well saturated colors; adequate resolution and good contrast ratio

Cons: Feels plasticky
Uses Samsung's connector in leu of the standard micro USB port.
As it comes in the box the OS lags a bit due to the liberal sprinkling of widgets.

Summary: First of all, if you are asking question along the lines of "iPad vs. Note 10.1" or "Nexus 10 vs. ...", this is likely not a tablet for you. It is a niche product designed for a very different purpose. Think of it as a Wacom tablet that happens to run Android. The pen works great for taking notes, of course, but it comes into it's own when you use it in Photoshop Touch or SketchBook Pro: you get 1024 level of pressure sensitivity at 1280x800 resolution (i.e. REALLY precise).
The "side-by-side" feature is nice, and is pretty useful, but the number of apps that can be used side by side is pretty small. Never the less, the clipboard and the annotation features work well.
As far as the hardware is concerned, it is more than adequate for the tasks you can throw at this tablet. One point I would make is that the screen is very sharp, so don't get fooled by the "it doesn't have Retina display" thing. Although 300PPI screen looks stunning, 140PPI is nothing to sneeze at. At the distance you will be using the tablet you WILL NOT see the difference. (I used to do prepress work some time ago and we considered 150DPI prints to be "photo quality"...)

Overall, I would recommend Samsung Note 10.1 if you intend to use the stylus to write or draw on screen as you would on a Wacom digitizer. Otherwise, get a basic tablet like Nexus 10, Note Tab, iPad or MS Surface RT (depending on which ecosystem you like better) - I bet you will get a better bang for the buck with one of those.
Bottom line: I absolutely love mine, but make sure you need a "Note" and not a regular tablet...