Only have 1 trip to SYD and two in MEL under my belt, but I like MEL a little more. For a big family trip to MEL, we chose NOT to rent a car for the first few days, as we planned out enough to do in and around MEL for the first few days that a car would have been a waste of money. Then we did a full week rental for the remaining 7 days, with day trips including the GOR, and many others. My wife is a planner, and typically for day trips we would leave the hotel by 8am, and rarely return earlier than 10pm, but sometimes close to midnight. With kids, I prefer not to switch hotels unless needed, so we find it easier to keep homebase the same, even if it means very long drives each day. I typically choose different routes to and from locations just to mix things up a bit, as it adds to the fun for everyone. Had a blast, and I put close to 2,000 miles on the BMW X5 rental in 7 days.
