It makes sense comparing Optoma HD131Xe vs Nebula Mars II because they both are able to give some premium features. Based on our rating, both projectors have the same overall rating of 6.6.
Advantages Optoma HD131Xe over Nebula Mars II
Bigger projection screen size: 38-301 inch vs 30-150 inch
Better brightness: 2500 vs 300 lumens
Lower noise level, 26 dB vs 32 dB
3D support
More HDMI connectors: 2 vs 1
Advantages Nebula Mars II over Optoma HD131Xe
Lower power consumption, 57 W vs 262 W
Wireless connection enabled
Longer lamp life (normal mode): 30000 vs 3500 hours