I know, I'd absolutely love to see the model with Radeon dedicated graphics! Alas, Best Buy generally requests downgrades since they're terrified of anything that costs more than $1,200 and won't stock them in store.
I've upgraded to matching 4 gig RAM modules and while the Windows Experience Index desktop graphics didn't budge, PCMark7 gained over 200 points, putting it 20 points ahead of the Zenbook UX31A (which isn't enough to call meaningful, but the new 4690 score is where I'd like to see the Samsung). With a single 8 gig RAM DIMM there was no improvement, so dual channel RAM is the difference. Honestly, I trust PCMark more than the WEI. It is weird that two machines with the same graphics card, resolution, chipset and Intel drivers can score so differently. But it seems that Ultrabooks with the HD 4000 either score around 4.6 or 5.5, with no clear reason and no difference in actual performance when transcoding video or playing games.