I had an 01 and now have an 2004.5 with the 600 Cummins.. No comparison IMO.. The new truck is quieter and has way more power. Fuel mileage is about the same but the 01 had 4.1 gears.. My nephew has the Megacab and that thing is sweet. Really my 04 doesn't seem to have much more back seat room than the 01 had..