I purchased the MK710 mouse and keyboard combo locally from another store. I primarily needed a mouse but bought the combo with the unifying receiver. The keyboard had some nice features. I especially liked the LCD display that showed caps lock and num lock status. However that is about all I liked about it. The flat smooth keys made touch typing very difficult. I rarely look at a keyboard when typing, and typically just put my hands on the keyboard and type. Not with this keyboard, you really need to look just to get your hands in the right position. The low profile keys have very little spacing between them which makes it very easy to hit the wrong key and you don't get the tactile feedback of the edges of the keys as you type. It's really worse than it would seem. The function keys were small and had alternate functions for things other keyboards have dedicated alternate buttons for such as launching email. This was marginally annoying, but I could have lived with that. My daughter who normally doesn't use my computer used the keyboard for just a couple of minutes and immediately commented about the keyboard. I really don't see the need for the low profile desktop keyboard, other than to make it look cheap, and to make it cheap. The whole keyboard looks and feels cheap. On a laptop there is a reason to make low profile keyboards, but not for a desktop keyboard.
The mouse on the other hand I liked, for the most part. The mouse is ergonomic and fits reasonably well in my hand. It is still a little smaller than the Microsoft Mouse it replaces, but works much better. The mouse movement is smooth and accurate and doesn't have any of the lags that the Microsoft Mouse had when left idle. The scroll wheel has two modes, a free wheeling flywheel mode, and another mode with the more typically click stop. There is a mechanical button to switch between the two modes. In the click mode it works fine and as expected. The flywheel mode is really nice but has some minor problems that seem to vary by mouse (more below). The flywheel works really well, and lets you scroll really quickly through web pages and documents. You can still easily control where you are, as long as your finger is on the scroll wheel. However when you let go of the scroll wheel, even if it was stopped, it moves, usually up and makes the web page or document move from where you selected. If you are extremely careful, and slowly remove your finger from the wheel it will do it a little less. It almost feels as if the wheel is unbalanced and if you let go with a "heavy" part up it will roll down. The mouse click is a little quieter than the Microsoft mouse, which I strongly prefer. It is easier to click and makes much less noise. The two side buttons (default forward and back buttons) are fairly well placed. They are a little small and tend to be slightly difficult to press, but overall they are fine. There is another almost hidden third button on the side that you can hit with your thumb. It defaults to displaying all open windows.
I subsequently returned the keyboard and mouse combo and bought the mouse by itself from Best Buy. While it is the same model, it seems much better and doesn't seem to roll by itself after you let go. There is either slightly more friction (although it still spins very freely), or is better balanced. Whatever the case it is better than the same model that was bundled with the keyboard. It does have some jitter though. When you let go of the scroll wheel it will sometime jump one click back and forth for a few times and then settle down.
So the summary is that I really didn't like the keyboard at all. While it had some nice features, the main feature of typing was in my opinion horrible. The mouse however I really like. Yes, the scroll wheel can be finicky and sometimes annoying, but overall the mouse is really good, and MUCH better than the Microsoft Wireless Laser Mouse 5000 that it will be replacing.