iPad is the clear choice. I do find it interesting that your big issue with the iPad is that it is "locked down", yet you would consider an iRex.... or any eInk device....
Anyway
You really can't go wrong with ether iPad or netbook. It really depends on what you will use it for. Do you want to run Windows software? Then get a Netbook.... Is battery life, portability (at least more so), and access to 200,000 plus applications are important? Get the iPad....
I own a Gateway 10.1" Netbook, with the newer Atom processor, and Win 7... Got it a month before I got the iPad... Let's just say the iPad is used a LOT more....