No hanging around with a flowery introduction - let's get straight to the point.
Great functionality - easy to set-up - superb brightness.
Expensive - poor sound.

First of all allow me to explain the title for those that are not aware of keystone correction.
'Keystone' has to be the most bizarre term doing the rounds in technology today and if anybody can use their language skills and explain a little etymology of the word I would appreciate it as I have no idea where it comes from.
A data projector can be positioned absolutely in front of the screen, or above the screen shining down or below the screen shining up. Usually they are at least 5 feet from the screen to obtain a reasonably sized image although some of the more recent products on the market can still get a large image from closer to the screen that this distance.
Now, if you get a torch and shine it at the wall you will see a perfect circle of light. Try moving the torch higher and lower and watch how the shape of that circle of light changes. Now, the data projector works in the same way. In front of the centre of the screen the image is a perfect rectangle showing the computer screen. As you raise the projector the top two corners of the image come together and the bottom two corners separate leaving you with a trapezium shaped screen. No good - and this is where Keystone correction comes in. Keystone correction is the name given to the function of the projector that allows you to adjust the image to bring back the rectangle.

The second point about this projector is the ease of use. This projector is easy to set up and a dream to use. I can't comment with any authority on the instruction book as I have never needed to use it. The remote control is totally intuitive and having been hung in its cradle we have never touched the projector or looked at the instruction book. Even people who label themselves technically illiterate have used this projector with ease.

The only downers are the price and the sound quality. This is not the cheapest projector on the market and you will find similar functions for less money. I would suggest however that the image quality is great and makes it worth the little extra. The sound is poor. The speakers are relatively quiet and tinny. No real base to speak of. However, adding even a cheap set of powered speakers overcomes this problem. Arguably for the money being paid you might reasonably expect a little more volume and slightly deeper bass. I would say this oversight is worth it for the portability of the unit.