Are you sure that wasn't to dampen vibrations which might affect (or even themselves be caused by) spinning the disk and movements of the read head? (Same reason there's concrete blocks in the base of a washing machine)
To vastly over-simplify our economy, we usually expect people with greater ability to pay to pay the same or more for substitutable goods. For example, people with more money can buy fancy coffee from starbucks, while typically people who can't afford that will make do with instant coffee.
In this case, the people with the greater ability to pay have to pay less.
That seems ironic to me, even though I know enough about the economy to understand why it happens.
Is this just not doing the same as the app currently does? It takes your location and provides a number of filters based on that. I'm not sure how them providing a filter around uber's location is any different, in regards to a users's privacy, to them providing a filter when you are in Paris for example
All of their "satisfied customers" look to be just random stock photos that appear on a bunch of different websites I am not sure I would be keen to hand my keys over to them