I just got the Samsung 13.3 inch 535u3c. Had just barely enough time to remove the HDD and put in my existing crucial c300 SSD in there. The HDD tray takes only a thin profile disk and not any standard 2.5 inch drive. Also, looks like the 4GB RAM is soldered into the board. It has only one SODIMM slot so I'll be getting a 4GB module today before I fully give it a spin. Max supported is listed as 8GB otherwise I was planning on adding a 8GB module giving a total of 12GB.
The build quality is definitely great and it compares to the 530 Intel based model. This is a first of sorts for AMD based ultrathin and I appreciate Samsung for not treating AMD like a step son. The machine surely feels light at around 3.2 pounds. Also the screen and body have minimal flex. It certainly does not fall in the same ball park as Asus ux31 but surely competitive.
On the OS front I do not run Windows. I have not even powered it on once with the stock HDD and haven't even agreed to the license and set up. So I am not certain of windows performance. My Linux install boots up in around 20 seconds and I am sure I can tweak it to boot faster. Suspend to RAM takes 5 seconds and resume is less than that even on linux.
I have never bought something this new and there was no prior reviews at all. I can write more if anyone has any specific questions.
Just to add to my note and clarify things. According to AMD trinity specs it has a dual channel memory controller. The laptop has only one memory slot, which is also empty. The other dimm is soldered into the motherboard. So to fully take advantage of dual channel controller one has to add dimm in the slot. I wish Samsung officially supported 8GB dimm.