Actually, only 4.5 stars

I would love to give the LED projectors from Acer C120 only 4.5 stars. Since this is not possible, I then round at times.
Half star I would deduct therefore because the device but has some flaws, but makes a very good impression.

Positives:
-tiny
Comparable to a 2.5 "External HDD
-Hell (At least for LEDs)
To recognize very well even when not complete darkness.
-Beautiful Colors
-Even Without power supply operable (via USB)
2 USB ports required

Negative
-Not Comparable to projectors with incandescent lamp
It's just one LED
-Keystone Compensation only to a limited extent
-Loud
The projector has to make the LED to cool 2 small fans the relatively large amount of noise.

Half star I would especially deduct because of the volume of the fan. Most of the time when a film does not hear the projector. For very quiet scenes, however, a whistle in the air. Nevertheless, I can only recommend the device, but one should remember when buying a LED Beamer always there is "only" and not a cinema projector.
Personally I use the projector especially in (student) residence to watch movies (more comfortable than a small laptop screen and Cheaper than a correspondingly large television / monitor).