We had a chance to test and compare two models: ViewSonic PX747-4K vs Optoma HD27 and this review should help people who are looking for a good projector. Based on our rating, PX747-4K has a total rating of 7.3 out of 10 versus 7 for HD27.
Advantages ViewSonic PX747-4K over Optoma HD27
Bring the cinematic 4K UHD experience home with the PX747-4K
Better brightness: 3500 vs 3200 lumens
PX747-4K is HDR-compatible
Advantages Optoma HD27 over ViewSonic PX747-4K
Bigger projection screen size: 30-300 inch vs 60-200 inch
Lower noise level, 26 dB vs 27 dB
Lower power consumption, 260 W vs 310 W
3D support
Longer lamp life (normal mode): 5000 vs 4000 hours