No problem with my MacBook Pro 2009 using the latest version of Mountain Lion. I also have the 2012 iPod Nano and the Bluetooth signal is strong and clear as long as the device is somewhere on my upper body, such as on a wrist or armband or in a shirt pocket. Jaybird specifically says not to put it in pants trousers or below the waist and explains why.
I own both Jaybird Sprint and the new Jaybird Blue (and Jabra Sport). I am an all Mac (10.8.2 ) guy. I've had no problems pairing with my Mac Pro 2011 and Mac Air 2012. No problems pairing with my 2nd Gen Itouch and new 5th Gen Itouch. No problem pairing with my Nano 6th Gen (you will need an BT adapter. I have a Kokkia and it works fantastic). I did have issues in the beginning with my new 5th Gen Itouch pairing, but now seems to work well with my JB Sprint and much better with the new JB Blue. I use my BT mostly for working out. I have not yet trued with phone nor movies. Hope this helps.