I am using this to teach small group photography workshops at various locations so portability was my biggest concern. The 40 inch size is just big enough for small group presentations. I would not recommend this size for large groups of people. As you'll read elsewhere this screen can easily fall forward as it's very light, has a very narrow base and its center of balance is slightly forward because of the small plastic locking foot on the bottom. I will be clamping it to an adjustable light stand so this is not an issue of me as I won't be setting it on a table for viewing.