They're really clean. The same goes for Cedrus atlantica and the Colorado blue spruce. Some trees that might otherwise fit into the landscape plan should be avoided for their aggressive and destructive root systems. They'll move concrete. And trees like poplars and cottonwoods are shedding all the time and should be avoided.
Oaks are real temperamental, too, especially around a swimming pool.
Redwoods work pretty well as long as you give them room to grow. You can start them low-branched and then after five to seven years trim back the lower branches as the trees mature, presenting an entirely new look. Green pears are nice, and I like to use them because they hold on to their leaves, are not really heavy rooted and provide floral interest in springtime. But instead of using a single tree, they look best in stands of three or five. Birch trees are also appealing when used in groups of three or five.