We have also had a glass roof with an under-roof awning for a few years. In summer, we almost always have the under-roof awning out, so that both the terrace slabs and the living room behind do not heat up as much. Besides the temperature advantage, of course you don’t see the dirt, because pollen, leaves, bird droppings, etc. always fall on the glass, and if it doesn’t rain for a long time, nothing washes it down. Twice a year we have the window cleaner come to clean from above and below, and if it gets very dirty, I also climb up from time to time armed with a hose and cleaning tools and clean it from above. That goes quite quickly with the large panes, and at the same time the drainage channel is cleared. We saw the louvered roofs at a trade fair. I found it very unsettling to sit underneath, and the panes were quite small relative to the louvers, so that very little brightness would probably come through. Also, I imagine it would be terrible to keep those things clean.