Only time i've had wireless user interface issues is at LAN parties when just about everyone is using the same brand and also using wireless...with that many people there tends to be some interference. Logitech is the only brand I've ever used and never had a problem. I love my trackball also its a trackman something or other where you move the ball with your thumb, I've gotten many a laugh watching others try and use it. They usually try and move the whole unit around and that's not how it works LOL.

Also my bluetooth apple keyboard that i use at work with my macbook pro works pretty flawlessly. The main issues with wireless IO devices is poor or low quality off brands and batteries. Re-chargeable batteries can cause some frustration as they are not always dependable but I guess that to depends on a good quality brand.