one of the main feature of the Epson ex31 , ex51 and ex71 be usb plug-n-play . this be theoretically a nice feature that simplify setup . you just connect a single usb cable from pc to projector , and it send all audio and video over that . unfortunately Epson do not have 64-bit usb driver for Windows Vista or Windows 7 . this be despite the fact that about 50 % of Windows 7 installation be 64-bit . this indicate poor planning and lack of commitment to the most common operating system platform . this may change in time , but as of now -lrb- October 2010 -rrb- , Epson technical support say the company have no public plan for 64 bit Windows support of this feature . therefore if you now have or plan on ever run any 64-bit version of Windows , just assume the Epson usb plug-n-play feature be not there . any evaluation of these Epson printer vs competitor should be minus this feature , as there be no current public plan to ever support 64 bit Windows . besides this , the projector work pretty well . it have multiple input : composite , S-Video , VGA and HDMI . image quality on hdmus seem very good and it be decent even on composite . the menu system be logical and easy to understand . however the fan be fairly loud , and there be a soft repetitive beeping from the printer . the acoustic noise be probably ok in a noisy classroom , but it be way too loud for a quiet environment . also the on-board speaker volume be limit , so if you presentation contain audio , you 'll need external audio for people to hear it very well .