Battery life is about 15 hours, and boot time is about 45 seconds (which is long enough to discourage turning off the device). This is good enough for all day use.
The iLiad is expensive, but it is the only game in town until large Vizplex screens become available (probably in ~6 months). The only announced product with a 9.7" screen is the V9, see
Hanlin V9 Early Review & Photos, but there are likely to be other devices with 8" and 9.7" screens. A large fraction of the cost of an e-book reader is the screen, so these may not be much cheaper than the current iLiad.