This reply may go part way to helping you decide what is possible with this great keyboard...
- first of all the supplied Bluetooth adaptor/ dongle is all but useless unless you just want to use the keyboard only. The trick of holding down the red button whilst pushing the dongle into a USB port works & turns it into a hub and you can use any BT mouse, however, the euphoria is short lived as the dongle has to be reset each time the PC is restarted! The button can be taped down (to keep the hub on) but the switch is so sensitive and before long you're retaping it, not very practical or reliable!
- it may have been true that no other BT adaptor was compatible when the keyboard launched approx 3 years ago, however, things have progressed/ changed. I received this keyboard 2 weeks ago and went about searching. To cut a long story short (and after trying/ wasting time and a bit of money too!) I realised other (especially non-branded) Bluetooth v2.0 adaptors did not work, however, newer v2.1 (EDR or no EDR) adaptors did, possibly due to enhanced "sniffing" capablities.
- specifically, for the past week I have been using a Belkin F8T016ng Mini Bluetooth Adaptor as a hub (pay no more than GBP 10, I got it from Staples for just £7.82), with no problems or resets! Unlike other dongles, I simply plugged it in, didn't use the supplied software & let Windows download the software... 5 minutes later with a one-off pairing done the "normal way" I am using it with the uptodate Setpoint 6.20.50 to customise the keyboard too! Oh and with a Logitech v470 Bluetooth mouse!!
What a relief and all this on a Windows 7 64-bit version PC too, that's a bit of coup!
It puzzles me why Logitech don't change the adaptor for one that works as a hub (as in the MX5500 and my old diNovo Media setup) as whilst I use the trackpad (especially with a PS3) I, and undoubtedly others, still require a mouse (ok, you can use a wired one, but thats simply not cool!)... anyway, I hope this story helps you 
