Good comparison review here:
http://www.bimmerfest.com/forums/sho...d.php?t=973239
I have been using Carly since my E60 M5 days but I have the Android version. I had to buy a Carly dongle last year ($70) when I got my F10 M5 since the generic dongle I used before no longer worked. The Carly dongle was worth it and can be plugged in 24/7 since it has an on/off switch.
When used with my Acer Iconia Android tablet, it's not overly stable so I have been looking at an IOS based coder instead.