(Note: I have also posted this review here).
This UX31A is a beautiful machine. Note that the R7202F is a UX31A-1AR4. It is roughly akin to a DB71, but it lacks a TPM, and has Windows Home Premium. It has an i7 1.9 GHx, dual core, quad-thread processor.
It looks far sharper than any Apple (in my view), and its construction is solid. It is light, sturdy, and it runs cool (the CPU runs at around 40 Celsius under normal conditions, and all the warmth is centre, above the keyboard). The IPS display is beautiful, and is perfectly visible in direct sunlight. Its brightness vastly exceeds other machines in its class. It is simply the best display in its class, bar none. The colours are incredible. The audio quality seemed quite good to me, though I'm no audio expert.
This machine has DDR3-1600, not 1333, as posted in many descriptions (I confirmed that it is dual channel @ 800 MHz). The one I received came with a Sandisk SSD (more on this later).
The battery life ranged from 5 hours (full bright, wifi on, backlit keyboard on) to 9-10 hours (low bright, wifi off, backlight off).
On the negative side:
1. The screen has some backlight bleeding. This is common on IPS screens, but if you need perfect blacks and watch a lot of movies on it, you might notice it. It isn't visible in normal use. Mine bled on the bottom right rather noticeably on a full black screen. This isn't a big deal for me. It is a shame, though.
2. The keyboard seems to miss keystrokes now and then. I don't think this was just me; other ASUS users encountered this on their machines. It occurs when typing very quickly. However, the keyboard is otherwise nice to use.
[Note that my second UX31A was much better on this point.]
3. The touchpad is unusable out of the box. The latest beta driver on the ASUS site gets it working well enough. You may need to disable tap to click as well; this is commonly an irritation on touchpads, because you can 'click' with your palm while typing. Note that if you need more configuration of your touchpad, Samsung has a driver which will run on the Zenbook Prime's touchpad, which also corrects the issues.
[Edit: Do not install the 1.0.32 driver, as it is about as bad as it gets -- it doesn't correctly reject palm contact, and it does reject normal finger contact. It is next to unusable. ASUS ought to try out their software before the ship it. The 1.0.26 beta driver works well enough.]
4. The unit I received would randomly shut down a few minutes out of sleep, every once in a while. This wasn't a bluescreen. There is no data in the Windows logs about the shutdown. Odds are, the machine lost power somehow. It happens whether the notebook is plugged in or not. This is a serious problem.
5. The Sandisk SSD is slow in small reads and writes. As in, it is terrible (4 MB/sec in some cases). I confirmed this myself. The alternative AData drive that comes in this laptop when there is stock is reportedly much better. That said, the computer ran fast. Most would probably not notice this.
6. There is too much Junkware on it. I removed the Trendmicro trial, the ASUS cloud stuff, and a few other trials. Just install Microsoft Security Essentials and be done with. When the antivirus makers can produce software that doesn't act like the malware they try to stop, we can use it.
Overall, this was a really nice machine. Some of those flaws are bad, but hopefully ASUS works them out soon.
I would have given this full marks for quality, except for the keyboard, mouse, and shutdown issue.