I purchased this clock last week, and have been very impressed.
The clock is well-made and entirely battery-powered (4xAA batteries), so there is no risk of electrical cords around the child's bed. Our 2.5 year old son almost immediately figured out how to use the night light feature, and he loves it. Furthermore, our son grasped the concept of "waking up to the green light" really quickly. I haven't had it long enough to be able to comment on the battery life expectancy, but given how much our son seems to be liking this clock, I suspect that this is a fairly minor issue.
A quick comment on the setup: it was remarkably easy to get going. Adjusting the wake-up time is identical to how one might set the time on a regular alarm clock. I figured out how to do it in about 10 seconds without having to read the instructions; that said, the clock also comes with well-written instructions in case you (somehow?) get stuck.
(I'm giving it 4/5 stars, only because I haven't owned it long enough to say how well it will withstand the test of time. So far, it seems really solidly-built, so I think it'll be fine.)