We tried the TV in New York City and had decent luck pulling in stations using the smaller telescoping antenna so long as we were close to a window. Moving into an office just about 20 feet away from the window caused us to lose the signal for virtually all the channels, but we were able to tune into most channels again once we switched over to the included "external" antenna, which is clearly more powerful. (The base of the external antenna stand is magnetic, so you can stick it to something metal and not worry about it falling off.) If you need an even more powerful antenna to pull in signals, you can purchase optional models that start about $20.
When we were able to pull in a station, the picture was clear and reasonably sharp and the sound played ample volume through the two small speakers on the sides of the unit. However, it should be noted that in terms of resolution the screen is only 480x234 pixels, which is standard for these types of $100-$150 portable TVs. That's enough resolution to give you a reasonable picture, but the individual pixels are distinguishable at close range and we're looking forward to the day when manufacturers can deliver higher resolution displays for about the same price. (You can get the even smaller Eviant T4, which has the same size 4.3-inch screen as the PSP, but it actually costs a bit more than the larger T7.)
As for battery life, it's disappointing. We got close to 110 minutes in our tests, which was better than the rated 90 minutes. However, that won't get you through a football or baseball game, and if the power goes out because of a storm, you won't get to watch for too long before the unit dies. What's worse: the rechargeable battery is sealed in the unit, iPod-style. That means you can't buy a new one when the built-in one eventually goes south. It also would've been useful to be able to swap in a bunch of alkaline batteries (especially during a power outage).
Another important note: because of the technical limitations of the DTV standard, this TV--like all portable DTVs--is not meant to be used while in motion (for example, in the backseat of a car). While we've heard reports that it sometimes works fine, it's just not something you should count on.