My iPad has now reached the point where, if I don't carefully set it into Airplane mode, Battery drains in 24 hours, even when asleep. I don't know if it's my mail client, or a background task being woke up by a geofence, or one of the GPS/WiFi radios - but I can't reliably leave it sitting around for several days anymore.
So, now I get into the game of "Disable Location Services for All applications, Disable Notification Services for All Applications, Turn off all Radios - NOW, turn on a small handful of services, and observe for a week - if everything looks good, turn on some more - keep doing so until the battery starts draining in 24 hours, and then try and identify the errant applications"
My #1 gripe about the iPad continues to be battery draining because of background tasks. If I could only "Force" the iPad into NO MULTITASKING, Single Damn Application at a time and NOTHING else mode, Don't Check Email, Don't Check GPS, Don't play music, Don't Download - I'd be happy. The only reliable way I've found of guranteeing this is to power it down - but it takes a long time (90+ seconds) to power it up each time I want to use it, which kind of detracts from the device...
So, no - iPad is not perfect. I would say 50% of my time this trip, when I went to use it, battery was completely dead so I ended up with my MacBook Air sitting on my chest to do reading.