My trusty TomTom Via 280 died a few days ago - since my brain died I've come to rely on it daily - had all my regular clients saved in it and just punched in the next job destination when I finished a lawn and then went back to sleep
I've been using my Android phone since and, while it's fine with spoken directions I find I prefer something dedicated on the dash - so I started to research the three main contenders here Garmin, TomTom and Navman - they pretty much all have lifetime maps and most have traffic alerts - more upmarket and you get bluetooth hands free for the phone and then wifi connection to do map updates so you don't have to take it out of the car
And then I stumbled on something I hadn't thought of - multistop route optimisation - to cut to the chase only Garmin units have it built in - how it works is you set up a multistop route and then have the unit create the most efficient route between all the stops for a saving of time and fuel hopefully - the other brands have the capability if you create a route on a web application, optimise it, save it in the file format for your GPS and then connect your GPS to the computer and upload the saved route - way too clunky for daily use
I don't usually do more than 5 jobs a day and have been working out my run order in my head each morning - maybe it's the best route, maybe not - but I reckon anyone with a big run might find the feature useful.
Edit: I hooked it up to the computer and updated gpsfix and now it's decided to work again so I don't get to go shopping - yet.