Being constantly on the lookout for newer, better machines, we gave in an purchased a navigator a little over a month ago to put into action. We have ran walkers for a long time, and had no complaints with the walkers, we just figured that the exmark had a few features that were appealing enough to make it worth a shot. Overall, the Navigator is a great machine. I won't go as far to say that it is superior to the walker, as they both have qualities that are better than the other. However, the exmark is the machine I end up with on my trailer every morning, and my walker is left for the other guys. Maybe it's just because it's new and shiny. To the nitty gritty (the things I think need improved on): 1. The front casters are junk. Actually our right front caster is fine...but the left front one bends simply going over curbs. Never in 1000's of hours did I have this problem with a walker. I contacted exmark about the troublesome spindle, and to paraphrase, they told me "tough s41t". That was a bit disappointing coming from the company that so many people brag about for their customer support. It's not that the caster is a big, high dollar part that we'll be out of pocket for, it's simply that a machine with 48 hours on it has a bent caster, and exmark (both coorporate and the dealer) has no interest in replacing it. Hopefully nothing major goes wrong, because I'd hate to see what kind of headache it will be to get something out of them that costs them more than $15 to make. 2. The Navigators has wires that run to the "full hopper" sensor that are relatively exposed to branches and new growth protruding from landscapes. A little rerouting of the wires and a couple of zip ties, and this is no longer a problem...just seemed like an elementary design flaw. 3. The back door on the hopper opens automatically when the hopper is tilted back. This is a neat idea in theory, but a major pain in the butt of a morning when cutting dew soaked grass that tends to clog the machine. The operator is pretty much stuck driving to the spot where he wants to dump the grass any time the machine needs to be unclogged. The auto-opening door can be worked around quite easily by removing a couple of pins, which we have done. Again, this isn't a big problem, but it does seem like something that was done more because it was a "neat idea" than for functionality. The good things about the machine: 1. Ground speed, ground speed, ground speed. Reason...self explanatory to anyone who has ever had to mow a larger, wide open area with a walker. 2. The height adjustments are .25" increments...very nice. 3. The deck is not as prone to "bucking" as the walker deck. This coincides with the ground speed for increased productivity. 4. Vent location on the hopper...I don't wear near as much grass that comes back at me from the vent on the exmark as I do when I'm on the walker. Again, the navigator is a great machine. Whether or not I'd buy another is still up in the air because of exmark showing no desire to stand behind something as simple and cheap as a caster. Hustler and Walker have both been great to us in standing behind their machines, even outside of their warranty, but exmark seems to have no interest in taking care of this incident. These type of things are generally a sign that the coorporate bean counters making the decisions for the company. Anyhow, i'm sure there will be some exmark loyalists who will come up with several reasons why the caster in question is bending because I don't know what I'm doing, and that there's no way it is just a bad part, but that's fine. I know how many years walkers were used on the exact same properties, in the exact same manner, and never had the same problem. Exmark has a start toward a great machine. It is a shame however that they apparently think that they are infallible and that they don't mind running off customers who were (or would be) considering switching their entire fleet to their machines. But hey, I'm not stupid enough to think that the machines we buy, or don't buy in a year will affect the amount of food on any of the exmark bean counters' tables....apparently replacing the caster would. ....(sarcasm intended). You exmark folks are right..the cut is great. I love the results. Just would like to see this awesome customer support that is frequently touted. Walker or Navigator????....depends on your dealer I suppose.