I be a teacher and be use two version of this projector currently in my classroom , the ex7210 and the ex3210 . this review include both general information about the two projector and describe the difference between they . General review of the Epson Multimedia Projector : applicable to both model the projector itself be smaller than I expect . it be also reasonably light and come with a carry case for easy transport . as teacher who move from room to room the portability be handy . the carry case have a strap long enough to throw it over you shoulder , a real plus when you be juggle stuff between classroom . the case have a front pocket for the power cord and remote as well . the manual and cd -lrb- for extra info -rrb- be originally packed inside this front pocket of the case . input : the projector be absolutely idiot proof when it come to input . you can push the button that say source search and it will find where you be try to input and start display the information . light output : light output be strong enough that powerpoint presentation can be see with the projector 20 foot away from the screen -lrb- this be as far back as I can get it in the room in partially light room . partially light in this case be define as the overhead light be off but the three window do not have blind . the room be bright enough that the student can easily see they papers and take note -lrb- and I can see the student ! -rrb- . these projector put out 2800 lumen -lrb- a luman be a unit of visible light emit by a source -rrb- . the school have 1500 luman projector , which I rarely use because the light have to be all the way off for the student to see the projection , and that lead to trouble . sound output : it have build in speaker and they be loud enough for use in a room with 50 student but just barely . in the smaller room with 25 kid it be great . if you use it with a laptop I would suggest add some speaker for sound . noise and Heat : they hum . the fan whir . not very loud but it be audible . they get hot , and fast . this be one problem because you need to let they sit for a few minute after use so the fan can cool the bulb down before you unplug it . that mean I have to remember to turn they off a few minute before class end . if you be leave it in one place this be not a problem . if you have to run , it might be . difference : want to watch movie ? you want the ex7210 with the hdmus input . I see two main difference between the ex7210 and the ex3210 -lrb- besides the color -rrb- . the first be the input . the ex7210 have HDMI input and a higher resolution -lrb- 1280 x 800 for the ex7210 and 800 x 600 for the e3210 -rrb- . the difference be clearly visible . if you be use the projector for video -lrb- or show movie -rrb- the ex7210 definitely provide a clearer picture . project on a screen from 10 foot away movie be clear , sharp and very little pixilation be visible . just want to use it for presentation ? if you be use the projector for business presentation -lrb- powerpoint and such -rrb- the lower end ex3210 be plenty good enough . I have often be use it to project a grid onto the classroom chalkboard for graphing . I can then switch to the next image with the answer and the student can see if they solution be correct . this be a godsend , as it be difficult to graph on a chalkboard with any accuracy without a grid . the projector even have a setting for the chalkboard , which take into account its greenish gray color and counteract the color change . it be bright enough to project a clear grid . the only small problem be keep out of the way so you do not block the image . and other use the projector can also be use in science class to project a clear slide of one color of light to show color absorption and reflection . I know this be not what it be design for at all , but it work very well for this purpose . I simply make a image of the various color I want to compare and since the projector use lcd to make the light the wavelength be very precise . although this will probably not be useful for most user it do show you how clear a projection the device yield . other issue : I originally try to use the projector with really cheap -lrb- think less than a cup of high end coffee -rrb- 25 foot long hdmus cable . this cause some problem , with the signal drop out every once in a while . Digital be either all there , or not . with a slightly better -lrb- think two fast food dinner -rrb- 25 foot cable I do not have this problem . the replacement lamp be currently just over 160 dollar on Amazon . since it be rate for 40,000 hour that be a lot of science and math . I can not speak to the price\/value for these projector -lrb- as I only have these and the school one but they be a lot better than the school provide one . everybody want to borrow they , and since they be easy to move around it be simple to loan they out .