I've got my fingers crossed for a Varia cam V2 with improved everything. After reading mixed reviews, I decided to hold off because $400 is not exactly money I can spend on a so/so product. If it can detect an approaching car, I wonder if they can also get it to disable/enable the light and/or camera as cars approach to extend battery life. Kind of like the concept of cars that turn on and off automatically when coming to a stop. I'm probably just dreaming about more tech features to potentially break, rendering the whole unit useless. But just a thought. It would be nice if it could make me breakfast, too.
My Fly6 bit the dust after, maybe 10-15 rides? The front Fly12 seems to be hanging in there, although a lot could stand to be improved with that as well in terms of camera quality/battery life/bulkiness.
I looked in to rigging an eBay cam to the rear for somewhere from $80-$120 as I recall, but I just felt I'd be wasting money. You get what you pay for kind of reasoning.
I do hear great things about the radar feature of the Varia, so again, hopefully they'll make improvements to it. It's an expensive accessory, but if it alerts me as a car approaches and gets too close and perhaps save my life it's well worth it.