I work at a charter middle school with a 1-to-1 MacBook initiative. Over the summer we got 200 shiny new MacBook Airs! (The newest w/ Magsafe 2. And don't get me started on the packaging -- it was absolutely awful.) I've noticed that the Airs are only reporting a wireless speed of 144Mbps in Network Utility. However, others Macs report 300Mbps -- in particular our older mid-'09 white MacBooks and iMacs. All of them are running 10.7.4. Does anyone have any clue why the new Macs are reporting slower speeds? We have a big fancy Xirrus access point which is operating on both 2.4GHz and 5GHz bands. I'm wondering if maybe it's an issue in the MacBook image? I've already done my due diligence kicking older / crappier wireless devices off.