I know it kind of goes without saying, but the linen Walts really are superb in hot weather. I have several pairs already that I rocked throughout last summer's record heat wave of like 42 days in a row over 100 degrees. God, that was horrible.
The tropical wool fabrics are great too, but because they're lighter weight than the Super 120s (or at least they have been historically), I don't find them to be as durable. I picked up the Pine ones because I really like that color, and have another pair in Worsted Pine flannel that will be retiring for the summer pretty soon.