As the new Logitech K830 hasn't been discussed much here yet, I thought I'd post a review (slightly tweaked from the review I posted on Amazon uk):
I've been looking for a wireless backlit keyboard with mouse functionality for a while. This is the best solution I've found so far even if it's not perfect (see below).
On the plus side, it works as advertised, is responsive, with automatic 2 level backlight, good range, and -it seems- good autonomy. No drivers are needed, although the Logitech software adds some useful configuration features. The support of Windows 8 gestures is also welcome with 2 finger scrolling, charms, etc.
The key selection is good, with useful features such as a sleep button combination, and it is possible to customise what happens for 10 pre-set key combinations (F2 to F8, shift Ins, shift Del). I wish there were keys for fast forward and rewind, but these can be fixed with some creativity.
Fit and finish is good, but not stellar, with some flex, a not-quite-flat touchpad, and a fairly weak power switch. The backlight, while good, doesn't fully light the white text on the keys unless one look straight above some keys ("enter" being the main culprit). The engraving in red is not backlit. Not a deal breaker, but it doesn't feel 'High end'
The main flaw in my view come from the absolutely flat surface of the keys, the lack of a built-in way to raise the keyboard when used on a desk (the rubber pads are too far from the edges of the keyboard to make it easy to lift the back of the keyboard without it slipping) , the limited space between the keys, and the not so precise key mechanisms. All this makes touch typing more difficult than with the Microsoft Arc, Apple and the old SK7100 keyboards I compared it to. It's definitely no Thinkpad/IBM keyboard even though one can get used to it.
All in all a very decent product, but it could have been better with just a few changes and I expected a bit more from Logitech at the full MSRP. This being said, the features combination is unique.