First off, please only reply if you run these machines. If you just have an opinion on what you think is better, thanks, but no thanks. I'm looking to purchase either a Walker GHS or Navigator. I plan on buying used (lightly used...) and I wanted to hear from people who run these machines if any recent fixes were very necessary to how they run. For instance, exmark made a few changes to the navigator within a few years of it coming out in 2005 I believe. Walker upgraded the size of the blowers in 2007 I believe and possibly the frames too. (Among other changes to each, of course) Should I try to only look at machines a few years old at the most? Or should I be okay with any year? Thanks!