I bought a Samsung Ativ and have been meaning to share a review… here goes 
First impressions: It feels very futuristic compared to my X60 laptop; Windows 8 and the hardware make it feel more like a big smartphone than a laptop. The stylus works fine for sketchbook pro, though I imaging it is possible to bog it down with high res or too many layers. Build quality is good, though they should have used metal covers imo. I like the design oveall and the detachable Keyboard is a cool feature which is fun to use.
After a week: Windows 8 is a big change - it’s like learning a new OS rather than a new version, though I do like it. Things take longer when your getting up to speed. Some programs are made for Win8 (like Explorer) and they work great, while others are not (like Chrome) and are harder to use. New features like the photo login are great… So is the email, metro start screen, and gestural controls once you get used to it. It was a little frustrating having to go slow to learn it all though
Screen resolution is way too high for such a small screen, at least with standard programs. Icons and menu items on regular windows programs are near impossible to hit with a finger, unless you tweak the settings for bigger fonts (once you do that, things are fine). Im surprised you have to do this for the stock OS it shipped with - Samsung should have set that stuff beforehand. Wide format makes your working area small in the vertical dimension, which is un-ideal for photo work IMO because the standard shaped images are very small when you view the entire thing + the bottom bar takes up screen space. The hinge doesn’t allow more than about a 110 degree opening, which works on a desk but it’d be better if it was more on the lap for example, though the screen/tablet is top-heavy and it’d fall over if it did lean back more.
There’s no way to to easily turn off the touchscreen when you’re sketching! This is frustrating. Lack of hardware buttons is also frustration coming from a Cintiq. For the keyboard screen connection, the lock is secure though occasionally the link between the two disconnects and you have to push the tablet down into the keyboard to reconnect. Last gripe, the 128 GB of hard drive space is barely adequate and without tweaking some of the automated backup settings and clouds services I have, the hard drive fills up fast. there is however a microsd card slot that would allow a 128GB 2nd drive upgrade. It runs 3D programs too; I’ve put Rhino on there but haven’t seriously pushed it yet… this is handy for rough shape underlays in SBP. Need to try SW or Keyshot sometime.
After one month: It’s great once your used to it and I really like it now, though I’d say it’s more of an ultrabook/souped up tablet than a mobile workstation (it really never fit that profile anyway). It’s great for sketching on the road, emails, surfing, content consumption and light content creation… Processor, Hardware, etc. are more than adequate for those uses… however a desktop workstation is going to be much more comfortable for normal workflow speeds.