i'm assuming that screens mean some contraption outside the window with a bit of free space between window and screen and tinting means applying a coating on the window's glass (i'm no native english speaker...)
if that is so, i would - out of personal experience - strongly advise to go for the tinted window. this comes from the following:
1. works better. i can't give any numbers (i never measured the difference) but it's cooler with tinted windows. this is for residential use, i have to add.
2. no loss of sight. for the screens to be effective, the window needs to be covered completely, or at least as far as there is direct sunlight. it's not really something important, but i prefer to see whats going on outside over seeing some grey screen.
3. less maintenance. with tinted windows, there's no additional moving parts, no additional power consumption (although that is probably negligible). and with screens, the need to clean windows doesn't diminish noticeably.
this is, as i mentioned, my personal experience with both systems in residential housing (my own flat). hope that helps,
chris