When I first saw the Apple TV box I was amazed at just how small this device is. It is so small and so light that you almost feel like you are getting ripped off, but that feeling goes away once you power on the device. Setting up the Apple TV was very easy, and the menus are extremely intuitive. It took me roughly 5-10 minutes to get it setup and streaming video from Netflix. Netflix's Apple TV interface is very attractive, and very nicely laid out. It gives you search functionality, Recently Watched, NewArrivals, Instant Queue and Suggestions. You never have to go to your computer in order to view, find, or play anything from Netflix. On occasion I run into some playback shuttering, but this doesn't happen very often and most of this is probably due to my shared apartment complex Internet that I am using. As far as a Netflix device, the Apple TV does an excellent job. (I prefer it over the Xbox 360 interface).
Airplay is of course the feature everyone has been talking about, but I don't use it. For me, the feature that really attracted me was "Home Sharing." Home Sharing allows me to play iTunes content from a computer, on the Apple TV. This feature is a VERY useful feature, and I love how it remembers where you left off (were you stopped/paused playback) across all devices. Again, Home Sharing was very easy to turn on.
Obviously the iTunes store is also available on the Apple TV. The iTunes store offers movies, and many TV shows for rental ($.99). The one complaint I have about the rental-only system is that you are unable to rent many shows through the Apple TV. In order to get TV shows that are not available through Apple's rental system you have to go to your computer and purchase them via the iTunes store. This is a little annoying, but it isn't the end of the world because after the show has downloaded you can then watch it on your Apple TV via Home Sharing (Nice!). Thus far the video playback from iTunes rented content has been very good, with no playback issues.
In addition to audio/video streaming you get access to YouTube, MobilMe, Radio, Podcasts and Flickr. Of these I have used YouTube, Podcasts and Radio. These are all nice features and work well, but not my sole use of the device.
All in all, I would have to say that I would definitely spend $99 all over again for the Apple TV. It has made watching TV without cable easier, and more enjoyable. The feature list is good enough to full-fill most all of needs, but the addition of Apps would be welcomed. If you have other Apple devices then the Apple TV will play very nicely with them, which is part of the reason I purchased it. If Hulu is a must for you, then you will probably want to look at a Roku, otherwise I would give the Apple TV some serious consideration.