I recently picked up a used MBA to finally go all in on the Apple ecosystem (handoff / continuity pushed me over the edge). It's a mid-2011 model that does have Bluetooth 4.0/LE. I'm running the Yosemite preview on it, and prior to DP3 it had the "Allow Handoff..." option in Settings>General. However, on DP3, that box is gone. I'm 99% sure this MBA will be able to fully handle handoff, so I can't figure out why that disappeared and it has me worried I bought one that's out of date. I'm also having a heck of a time connecting my 5S (on iOS 8 beta 3) via bluetooth. Thanks!