The equipment is only as good as the ones fixing them and setting them up to run, around me, granted I'm in the middle of nowhere, there are few and far between persons who set up the programs to run the gps units in the first place, they were trying to sell them to those that did nrcs work for the county and state offices, not bad my local county office isn't up to even using lasers yet, let alone even knowing what gps is, let alone coming up with anything to resemble a program to do the job, so its up to the consumer who buys the gps to write or setup their own programs for each job, now if your up on gps to be able to do that, then you still need to be able to have a signal to run them or enough satalites to give accurate measurements, most times in the terraine I'm in and the locations we work that's not possible, if your working around and under tree's or in a ravine or ditch, too close to buildings they still won't work, now toss in the weather situation where its cloudy or rainy and some satalites are no responding you have a nice looking high priced boat anchor. If your on state or highway jobs or big construction jobs they might be the ticket for guys like me, the units cost more than the dozers I'd put them on and the type of work I do lasers and machine controls are definately the way to go, more cost effictive and user friendly and work a greater majority of the time and have local people who know how to fix and trouble shoot them. I too love technology and given enough time gps will too come down in cost and reliability will come up to all areas like it might be in your area.