Hello everyone,
Thanks to Lenovo I had the opportunity to test and use the new Yoga 900S. As I also have Yoga 3 Pro I'll also compare the two.
Size, weight and build quality.
Yoga 900S is smaller and lighter (by 200 grams). However, they're both skinny 12.8mm thick.
The materials appear to be the same, but somehow 900S has much more metallic feel to it. It also feels more sturdy. It might be related to the smaller size of the 900S. The case on the inside has more of a leather feel to it compared to the rubbery feel in Y3P.




Keyboard:
I have mixed feelings with this one, because:
+ dedicated F~ key row - great!
+ 2 level backlight - love it too.
- much lower key travel compared to Y3P, but still comfortable enough.
? awkward placement of the right shift key. This could just be me, as I got used to Y3P's layout, which had the right shift key on the left side of the up arrow key instead of the right side.

(picture by Cnet)
Touchpad:
Slightly smaller, but still comfortable to use. I have no remarks. It does its job. It happened couple of times that the cursor jumped to the bottom right corner when I tried to click using left index finger while swiping with the right index finger. Not sure what happened, but it was so minor I'm suprised I still remember it did!
Screen:
The model I received has a Full HD screen (1920 x 1080). I've seen 1440p being mentioned around the net, but this particular model definitely has a FHD screen. I currently do not have any tools to measure the specific properties of the screen, but it does look very good. Colours are vibrant, and the contrast is also very good. I like this resolution, as there's no need to change the DPI of the screen to make desktop items bigger. Some applications do not work very well with any DPI other than 100%. Also, unlike Y3P, which has a pentile pixel arrangement I believe 900S has regular 3 subpixels per pixel matrix.
Unlike Y3P, 900S has a full-glass front. There's a plastic stripe right above the hinge in Y3P.
It was announced it has an inbuilt active digitizer, but as this one did not have the pen I could not test it.
The touchscreen is accurate and responsive. In 100% DPI mode some of the items might be too small so you should consider increasing it if you use touch a lot.
CPU:
Yoga 3 Pro: Core m 5y70 1.1GHz (2.8GHz turbo)
Yoga 900S: Core m7 6y75 1.2GHz (3.1 GHz turbo)
The newer Skylake CPU in 900S is an improvement, but not a huge one. There's not much to tell about the CPU itself... The first m series processor disappointed some people, but I have never had any problems with either. What's very satisfying is that this time Lenovo delivered a laptop according to Intels promises - 100% passive cooling. I only ran PassMark test (results below), but if you'd like me to run some other test please let me know.
GPU:
This is supposedly a big improvement over the Broadwell SoC, and judging by the benchmarks it is true. I started a 4k video on a freshly started 900S and there was almost no change in the CPU utilisation and the video played without any issues.
Storage:
This unit came with a 512SSD. It's a PCI-X4 M.2 card based on Samsung chips. I run Crystaldiskmark and... I was blown away. This SSD is seriously FAST.

For a comparison the results from the 256GB Y3P:

Ports:
On the right side we see exactly the same set of ports, yet with fewer controls. The volume and rotation lock buttons are gone while the recovery button went to the other side. Big plus, really big plus for moving the power button further towards the screen, as it's extremely easy to press it accidentally on Y3P. Imagine holding it with two hands by the sides... yeah. The button itself is also bit skinnier which also helps.
On the left side:
Exactly the same charging port as on Y3P, however this time the bit in the middle is orange not yellow. From here onwards more changes. Instead of another USB 3.0 port and an HDMI port we get a single USB C port which can cover both tasks (i.e. USB port or video-out). The next one is the recovery button. Unfortunately there is no more SD card slot. Not a deal breaker, but I'll be missing it a bit :)

Benchmark:
I ran Passmark's PerformanceTest. Some results are suprising, but it could be related to some differences in the conditions (running apps, drivers, etc).


I couldn't help myself and also had to take a peek inside :) 900S on the left, Y3P on the right. After removing the screws around the edge the cover comes off easily. As you can see there's absolutely no fan inside the 900S. Not sure why the speakers also got pushed back a bit towards the back, but alike Y3P they provide suprisingly good and loud enough sound.

Battery life.
Compared to Y3P the battery's capacity grew from 44Wh to 53Wh
I'm happy to anounce this time Lenovo definitely got it right. The advertised 10.5 hours is easily achievable. I used it at work everyday last week and I got runtimes between 8:01 to 10:52 (just powercfg output). I've yet to run a synthetic batterytest though.
Notes and summary
It's a real pleasure working on the 900S. As I'm constantly on the road it has the perfect size to be carried around. I'm happy Lenovo decided to somewhat split the premium Yoga series. Now, we have a thicker, but much more powerful Yoga 900, and still the thinnest convertible 900S tied with Y3P. Both have addressed different issues with the Y3P gives user a choice to choose the one which is closer to his or hers requirements. It's style and extreme size catches people's attention. I was really surprised once, when one of my clients directly asked me "Is that a Yoga?" :)
If there's anything you'd like me to test go ahead. I'll try to make it clearer whether this device is for you or not!
More benchmarks:
PCMark: 2350
http://www.3dmark.com/results/pcm8hm3
Geekbench3: single core 2075 multicore 3950
http://browser.primatelabs.com/geekbench3/5289855
3D Mark 06: 5127
http://www.3dmark.com/3dm06/17862089?resultRegistrationOutcome=KEY_IN_ANOTHER_ACCOUNT_CURRENT_ACCOUNT_FREE
CompuBenchCL
Face detection: 14 MPix/s
Optical Flow: 2.1 MPix/s
Ocean: 133.8 fps
Particles: 106 MInt/s
T-Rex: 0.9 fps
video: 5.5 fps
Bitcoin: 17 MHash/s