i put a a post years ago comparing the two. The weight issue is a non issue really because it's so minute, the weight of the operator can make the difference between the two machine. I'd drather have the better built machine which weighs a little more........Navigator. Exmark has dump bins for the Navigator. I've held them in my hands and seen them in the mower. We be available as an accessory to current owners. Changing belts takes about the same time for me on both machines. Both are pretty easy in my opinion. Navigator has one serpentine pump belt, and a double belt set that runs the blower/drive shaft. Walker has a belt for the blower, a belt for the pumps, a belt from the engine to the drive transfer, and the pto belt. Navigator will never have a side discharge deck. That's why they build the Lazer. People buying the Navigator is are buying it for a dedicated bagger. Walker has been around alot longer and some guys have no reason to try something else, but there is always something else and the Navigator is the first "something else" that really competes with the Walker. Navigator is not discontinued from Exmark like some guys keep posting. They are starting to add more options, including possible engine options for next year other then then what they offer now, but I doubt you'll see EFI motors. They are not as fuel effecient on a machine like this that you are engaging and disengaging the blades more then you would on a z cutting bigger areas, so the extra money on top doesn't justify it. I had a bunch of pictures on here comparing the two. There's plenty of info but there is a bunch of guys who post on here that have no first hand info and put rumors and speculation and have never even run half the equipment they talk about. Both are good mowers. Best post I seen about the 2 is if you are looking for a machine with all the different attachments and what not, buy a walker. If you are looking for the better mower....but the Exmark. I would demo them both and see what works best FOR YOU, not everyone else. I don't think you would go wrong with either.