AAXA P3 are up against stiff competition lately, with a new class of slightly larger, much brighter choices available. The P3, for example, is rated at 50 lumens (and scored lower in our tests) compared to ratings of 200 lumens or more for pocket projectors which are the next step up in size and price. That said, smaller pico projectors like the P3 still have the advantage of literally fitting in a shirt pocket (as long as you don't try stuffing in the power block and adaptor cables with it). The small size by itself is enough to make them worth considering.
AAXA's pico projectors tend to offer extras that make them stand out. For the P3, the extras include a full size HDMI port and a native widescreen resolution, at 1024x600. (The actual aspect ratio is about 16:9.4, but I'll refer to it as 16:9 here, since that's what the P3's menu system calls it). Also worth mention is that the P3 accepted input at 1080p in my tests, even though AAXA claims a maximum input resolution of 1280x768.
The key shortcoming for the P3 and other pico projectors its size remains the low brightness. However, the P3 is brighter than earlier generations of pico projectors, which were rated as low as 10 lumens, so it's certainly bright enough to be useful. And the $269 price is more than a little attractive for a projector you can carry with you easily, run from batteries, and connect to computers, composite video sources, USB memory keys, and anything with an HDMI port.