Proprietary Power Supply? And then not even the manufacturer's website to offer? - No thanks Lenovo!

The problems described in this regard. I can not confirm the performance altogether. The performance is really great.
I have tested both the stream Amazon Prime Instant within a 54Mbit public WLANs, as well as the Blu-Ray Stream (1080p / 24) within a 300Mbit-WLAN network and parallel applications with all the WLAN standard "n" so hergibt - I never had any problems, stuttering or otherwise.
At this point it may be said that one can not expect, with the basic settings, as well as with the pre-installed (Microsoft) software (se times except for the system) to benefit from full power :)
I use to browse, stream, and what is still so present, primarily open source.

Problems with the docking of the keyboard there was no, the handling was OK.

The screen brightness is perfectly okay, I use rarely the maximum value. You just have to just, as mentioned above, change the basic settings and if necessary disable the "adaptive brightness".

Overall, I was really pleased, 1.5 weeks that I was able to use the device, but now the absolute knock-out criterion:
The charger ...
Lenovo sets here in seemingly usual manner, a proprietary power supply with a voltage of 20V at 2A in, which means in plain language that you can not use a standard power supply, as it is known from notebooks or netbooks. That a tablet or smartphone PSU can not work, it should be clear, as these usually provide only 5V at 2A, what a device of this type (assuming you do not want every time to load 24 :) of course can never be enough.

Since my power supply was already broken but now when buying, I for interest held by substitute out. The established online stores no offers. Amazon itself initially offered me a discount when I but it drew attention to the fact that a replacement was apparently hard to come by, the colleague did himself first on the search - at this point again a big compliment to the Amazon service! When contacted again me Amazon, you also had to admit defeat after an unsuccessful power supply search and offered an exchange to me.

This circumstance would be fine (it may, after all, sometimes a production errors occur) when at least Lenovo would offer themselves an appropriate replacement PSU. But neither the search on the manufacturer's website, nor a support request have been delivered results. If Lenovo still be heard from, I'll be happy to add the answer here.

Conclusion:
Without charger also the great power does not help, so only 1 star!
Furthermore, it is impossible to put in a 500 euro device to the WLAN Stanard "n". Every smartphone in the price category is already using "AC". But these cheap driving strategy so apparently most manufacturers in the 2in1 devices ...