Disclaimer: I have never flown this model, just the Phantom 2 Vision.
There are two basic Phantom models: the original Phantom (like the one for sale today on Woot) and the Phantom 2. Either one can be purchased with or without an integrated camera, with or without a camera mount. A camera mount that tilts the camera to keep it level when the copter tilts (which is how the copter steers itself around the sky) is called a gimbal.
The current state-of-the-art Phantom is the Phantom 2 Vision + which is a Phantom 2 with an integrated HD 1080p 30fps camera and a three-axis (3D) gimbal, MSRP $1299.
The Phantom 2 Vision has a different 1080p 30fps camera, with a 1D (tilt only) camera; since the introduction of the Vision +, I have seen the Phantom 2 Vision going for under $900 on eBay.
The FC40 for sale here has no gimbal; so whenever the copter tilts, to go forward, backwards, left, or right - the camera tilts also, so your video tilts as well. Even just hovering in place, you will see the small movements the copter makes to control/maintain its position. You cannot adjust the camera tilt in flight with the Phantom FC40; you can with the Phantom 2 Vision (Vision means it has the built in camera and 1D gimbal).
The Phantom 2 uses a proprietary battery that has its own built in charger controller/battery level meter. It allows for 25 minutes or so of flight time. It costs $159 per battery. This Phantom for sale here uses more widely available batteries, which cost anywhere from $25 to $50, and allow for up to about 15 minutes of flight time. Battery swapping is easy on both models.
The Phantom 2 has better flight control and GPS return to home features. How much better - hard for me to say but on message boards, pilots who have upgraded say they can notice the difference.
I have had no fly-aways - in fact, I routinely fly my Phantom beyond the control distance, and let it automatically return home to me. The trick here is that when the Phantom loses control, it rises to about 20 meters, then flies back to above its origin point, then descends. So you have to take off from a spot where the Phantom can ascend/descend straight up or down about 20 meters (i.e. don't start your flight under the canopy of a tree.)
Most of the message boards report that fly-aways occur when the pilot does not have the Phantom set to all the "automatic" settings, or did not calibrate the compass before flight (takes about three minutes), or had some sort of non-standard WiFi setup.
I'll watch this board today, try to answer any further questions/criticisms I can.
And yes, I am very happy with the money I spent for my Phantom! But I would consider saving up for a better model, as after you enjoy flying this one, you'll be hooked!