longer races for sure...
at one of the clubs I race at there are too many classes (sometimes over ten), frequently with only 3-4 cars in each race, which then means we only get two 4 min heats and one 5 min final. which means a ton of effort for only 13 min of track time.
I would prefer to see some longer races, with less classes, and each race being "fuller" ie not less than 6 cars. racing two classes at once (eg novice + mini, brushed stock + brushless stock, 2WD and F1, 19t + mod) would mean that we could get more track time, either by running longer races or more races or at least a longer final, and still keep to about an hour or so between each race.
hmmmm, food for thought...