It makes sense comparing ViewSonic PA503W vs Optoma UHL55 because they both are able to give some premium features. Based on our rating, PA503W has a total rating of 6 out of 10 versus 9 for UHL55.
Advantages ViewSonic PA503W over Optoma UHL55
Bigger projection screen size: 30-300 inch vs 30-200 inch
Better brightness: 3600 vs 1500 lumens
Advantages Optoma UHL55 over ViewSonic PA503W
Bring the cinematic 4K UHD experience home with the UHL55
Lower noise level, 28 dB vs 33 dB
Lower power consumption, 170 W vs 260 W
UHL55 is HDR-compatible
3D support
Wireless connection enabled
Longer lamp life (normal mode): 20000 vs 4500 hours