Once upon a time, I paid $160 for the Logitech MX for Bluetooth. It was a great desktop set, no lag, no problems, great volume control, great bluetooth support and connectivity, truly the desktop of the gods.
3 years later, the keyboard stopped working. Dead.
I called Logitech, and they said they didn't make it anymore, but they'd send me a newer, nicer version of the same thing. How could I go wrong I thought!
What they sent me was, without a doubt, the worst piece of consumer electronics I've ever seen in my life. The bluetooth connection drops frequently for the mouse and keyboard. The mouse will lag between 1 and 3 seconds behind your actual movements for minutes at a time. The keyboard will say, "The letter 'd' eh? Have 300 of them!" And type them all out. Or, if you were pressing backspace at the time your keyboard skitzed out, you get to lose everything you were typing!
Well this is no good, said I. I call Logitech and explain the problem to them. They quickly decide to send me a whole new set! Unfortunately, it had the exact same problems! The problems are at their absolute worst when Logitech's Setpoint is installed. I went to the Logitech forums to see if there was a solution. All I found were thousands of angry users.
So I have the following suggestions for you:
1) Google "MX5000 sucks." There are hundreds of reviews, web pages, and message board posts to be found.
2) Check out the Microsoft Entertainment Desktop 8000. It's better in every single way. I'll never buy another Logitech product again.