I notice that there are some folks who get concerned when they are lacking on time and wait 30 seconds between reps instead of a minute, but I think that's fine. It often forces you to get an aerobic activity on a weight day, and it forces you to use a little less weight as well. Light and rapid equals good.
Another thing I do is mix up the way I do upper body. Some days I do Chest, Shoulders, Back, Triceps and then Biceps. But sometimes I do the exact opposite. I think it's neat because on the days I do the former by the time I get to Biceps I can't lift that much. Yet on the days I do the later, I find I can lift almost twice as much with my Biceps. So I think it's good to mix it up.
I think the next time I do such a workout I'm going to do back first, because that usually gets tossed into the middle. I wonder how much weights I could lift with my back muscles if they were fresh.
I also think it's good to do a variety of aerobic activities, such as basketball, racket ball, sprinting, etc., as opposed to getting on the treadmill each day. Yet in the winter the treadmill is the only option for me. So most days I do interval training, yet sometimes I mix it up and run at a slower pace and go for distance. Yet since time is usually precious, I usually have to do the interval training.
So mixing it up is good.