I've used a similar provider, Stephouse in Portland, OR and they would routinely install repeaters throughout the city to help cover deadspots, areas shaded by tall buildings, hills, etc. I assume the same would be available in Philly with the advantage that Philly is quite flat by comparison.
Do these repeaters also require line-of-sight to the consumer, or do they use a different means of communication?
(Also this sounds a lot like an ordinary provider and not like the independence as claimed on the website. A mesh networking solution would achieve independence through peer-to-peer connectivity.)
Mesh networks at this scale are pretty complicated and messy. Also they tend to be pretty low capacity. It's an order of magnitude (or maybe two) more difficult to build and manage a high-capacity robust mesh network than to build a pure line of sight hub-and-spoke style network. (I've done both.)
