I stopped buying BT keyboards and mouses for this exact same reason. Now if I buy wireless, I go with a a product that comes with it's down dongle and wireless protocol. Like logitech.
Hmmm... I'm able to use my BT headset, Apple trackpad, third-party keyboard, and an old SonyEricsson mc600 all on the same MacBook Air with zero problems, other than the appallingly short battery life in the (now retired) trackpad. This is immediately next to an iMac with Apple BT keyboard and Apple BT mouse, again with zero problems.
Is it possible there's something else in your environment interfering with the BT signal? Perhaps an office with lots of other BT connections?
> Is it possible there's something else in your environment interfering with the BT signal? Perhaps an office with lots of other BT connections?
Bluetooth uses the frequency range between 2,402 GHz and 2,480 GHz. This is in the ISM band that is also used by Wi-Fi. Indeed according to the German Wikipedia article on Bluetooth (I could not find such a remark in the article in the English wikipedia)
I use them all the time, BUT I have noticed that if they are paired to more then one device I will sometimes have an issue if I had to re-pair to a device.