If you don’t need GPS Navigation and where breadcrumbs will do and you don’t need an oversized/large screen then the Edge 500 is a fantastic piece of kit... and as Dave has said no smart phone functionality.
The screens are fully customizable so you can get by with scrolling through screens and having a large display on each, the battery life is phenomenal and it has buttons ~ This is a huge advantage during the cold weather where you have thick gloves, buttons just make much more sense and I believe the new Garmin Edge has moved back to buttons.
The Edge 500 is showing its age is some areas, power metrics and configuration of power is one such area but if you don’t use these silly things then you’ll be fine.
I would highly recommend the Edge 500 if you’re look at this type of device Tom.