It makes sense comparing Optoma ML750ST vs Epson PowerLite 1781W because they both are able to give some premium features. Based on our rating, both projectors have the same overall rating of 7.
Advantages Optoma ML750ST over Epson PowerLite 1781W
Lower noise level, 22 dB vs 39 dB
Lower power consumption, 77 W vs 309 W
3D support
Longer lamp life (normal mode): 20000 vs 4000 hours
Advantages Epson PowerLite 1781W over Optoma ML750ST
Bigger projection screen size: 50-150 inch vs 30-80 inch