I have one, top bit of kit to be honest. I have a car kit, and also bought the bike mounting kit aswell. I have the bike mount fitted to my VFR, and it fits fine, not sure about the double bubble on the 999 though...
I bought mine from a company in Scotland that were selling on eBay, (I forget the name now), but I got lifetime free updates for my unit, and all in all, the price was, (with the fitting kit), 150. Oh, I also got the mobile detector chucked in.
I think 150 is a bit pricey to be honest, when you consider a friend of mine just sold his Classic on eBay for £70, mobile alert and bike fitting kit included.
Another option of course, which I use (because these days the Road Angel is hard wired into my car), is get a Garmin i3 Sat Nav unit, I bought mine for £99 from Somefield, the download the speed camera update. This then gives you exactly the same as road angel, i.e. all gatso, specs, mobile sites in the UK. And, the unit is so small and portable, it will fit on the 999 screen real snug.
So, £100 ish, and you will have a sat nav system, and a speed camera detector. Result.
Oh, and the download is free