16 of 18 people found the following review helpful
Don't buy this product until you have checked 'Severe Latency',
This review is from: Logitech Wireless Combo MK520 - UK layout (Electronics)
I bought the Logitech K520 wireless keyboard and mouse after reading positive reviews on the web. I had just bought a new desktop and wanted a better keyboard than the one issued with the new computer. The K520's design is good looking with lots of bells and whistles - except that it doesn't work. Or rather, it works intermittently.
THERE IS AN ANNOYING TIMELAG BETWEEN USING THE K520 KEYBOARD AND MOUSE AND THE COMPUTER'S RESPONSE - IF IT RESPONDS AT ALL. This makes using the K520 absolutely frustrating.
I sdvise you to look up SEVERE LATENCY WITH THE K520 WIRELESS KEYBOARD - see forums.logitech.com
I noticed that when I typed using the K520 keyboard, the letters didn't always immediately appear on the computer screen. Sometimes they did appear. Just as often they didn't appear at all. Sometimes the words appeared after a delay of many seconds. Often when the letters eventually appeared on screen some letters of a word might be missing.
The same thing was happening with the mouse. One moment it was working fine, the next the mouse pointer was frozen on screen.
All this work, not work, partly work drove me crazy and made using the K520 a nightmare of frustration. Writing text or controlling the computer with the mouse was totally unreliable.
I thought that the problem must be due to a faulty wireless connection with my new computer. Perhaps the computer was causing the problem. I persevered hoping that the fault would clear. Eventually I could not stand the annoyance of using the K520 any longer and I searched the web for answers.
Lo and behold there were lots of people experiencing exactly the same problem as me. The all described this annoying time lag and the frustration this caused. If you look at Logitech's own website they have nothing but the most glowing reviews of the K520, but do an internet search using the words Logitech K520 delay,time lag or latency and you get a different picture.
Have a look for yourself at forums.logitech.com