Excellent topic Dan!
All my plants are planted in the ground, in full sun, all day long, whether they like it or not, because that's where my garden is located. Besides that the garden is surrounded by trees on 3 sides, and a hillside on the 4th side, so that almost no wind reaches the plants in the hottest part of the summer. But maybe my experience with a few different varieties all under the same hellishly bright, hot conditions would be helpful—
Like theghostpepperstore said, Tabasco seems to take a lickin' and keep on tickin' no matter how hot or bright it gets, producing at near optimum levels throughout the hottest months of the summer. Similarly, none of the chinenses seem the least bit rattled by full sun, except for blossom drop in the 95ºF+ weather. Most all annuums seem to sag in the heat of the day, and produce significantly fewer and smaller fruit in the very hot months, with the exception of Thai Chile (smaller leaves), which behaves more like Tabasco. The New Mexico types and Piment d'Espelette do poorly in the middle of the summer here—The plants almost stop growing completely, develop all kinds of root and leaf problems and the few fruit they produce are prune-sized. In the cooler months they don't seem to ever really recover from their midsummer suffering. I suspect, however, that our high humidity may also have something to do with that. California Wonder and Poblano, which have honking huge leaves, produce miserable, stunted, tiny fruit during the long, hot days, but in the later, cooler months I will get nice big, juicy, pods. As for baccatum, the large-leafed Aji Amarillo plants continue to grow but produce absolutely no fruit in the long, hot days, but in October there will be some very nice pods 6-8 inches long. Guampinha de Veado, a small-leafed, small-podded baccatum, seems to produce well all summer long...