I will keep this review brief, as it is supplemental to Art's full review, available here. Keep in mind that this projector is tiny, and it is only 480p. It is very portable and easy to use. In the time I spent with the P4X I tried a little PC gaming, but mainly stuck with the Xbox 360 and PS3. I wouldn't recommend this for PC gaming, because of the 480p resolution. It however does work great with the PS3 and 360. I mainly played Red Dead Redemption and Street Fighter IV on this little guy. As stated the lag (or lack of) was perfectly acceptable while gaming. The lag test results are available in my other P4X blog here.
I know this projector is geared mainly toward the traveling business person, and I think it would be best suited for that. It would also be well suited for gamers who are more concerned with portability, and resolution is secondary. I wanted to hook up the Wii on this projector, but unfortunately I did not have the proper adapter. Since the Wii is 480p, I am sure it would have looked amazing on the P4X. The color was great, and the brightness was perfectly fine in a room with a minimal light. Since the projector is rated at 80 lumens, I would not suggest anything larger than a 60 inch screen for gaming. If you have a completely light free room, then larger would be fine.
The P4X also has an audio out, so you can hook in a set of powered computer speakers, and it has a mini HDMI output available as well. It is also has a mini SD card input that will work with stored images/video, or audio. With a quick Google search I found this projector priced at about $290, which is less than most comparable projectors.
I would recommend this projector to business people with gaming as a secondary goal. Maybe you'd like to hook in your tablet and play an Android game on a big screen. Or your friend is console gaming on a 19" LCD and you're not going to take any part in that, so you bring this little guy along. Or a travel projector to show of home video and family photos. There are a lot of possibilities with this great little projector, gaming is just not it's strongest.
I love the portability of pico projectors, but they just aren't quite there for gaming. I spoke with Peter at AAXA, and they have some pretty fantastic ideas on how to take these LED projectors to the next level. I can't wait to see what AAXA will have to offer in the near future.