RedJet
In my reading, I understood that Apple have never fully disclosed what "Assisted GPS" is and I thought it primarily used mobile tower triangulation rather than GPS. But I'll stand to be corrected.
However, while Apple do not disclose the GPS engine specs, I'm sure it will be only a 1 Hz engine which I would not regard as adequate and it will suffer satellite reception degradation when its on your knee in the cockpit. I've certainly seen some ipad reviews for aviation charts where the reviewer has had difficulty with the ipad GPS signal (aviation consumer magazine).
Call me old fashioned, but I like a separate 5Hz engine on the glare shield with a good view of the sky. I understand this can be achieved with the ipad by using a bluetooth engine, but until Jeppesen make flitedeck / Jeppview available for the ipad, I have a bias toward a Windows device with a Garmin USB GPS engine as my primary reference. When ipad2 becomes available here, I'll use it as secondary reference to my LS800 (which will be replaced by a CL900 when its released). To keep sleepy CASA happy, there is paper in the back.