Without recommending or teaching you to use Kismet in a LINUX build to passively monitor bandwidth, you'll have to rely on your instincts and referrals including your neighbors, the BBB or even YELP.
The advantage of a WiSP is the collective communal nature so you wont' be the first pioneer to discover poor service, demand a list of (albiet biased) references but try to determine the user experience from those around you.
Your initial question was rife with apprehension and you've already determined for yourself this deal seems too good to be true, the fact the provider doesn't list references and user experiences, is very small and has only a barren web site is answer enough they're devoid of a positive or any reputation.
Some specific pitfalls to keep in mind when selecting a WISP mesh is the distance between yourself and the backbone, essentially to the point where the WiFi connection becomes a traditional ground connection. This is especially important in mountainous areas such as the Tennessee mountains since microwave signals are more susceptible to physical interference including blowing trees.
An emerging point to consider is whether the WISP uses Meraki equipment, the founders of Meraki practically invented the WiSP concept and were the first to be bring it to market and were widely embraced for using "open source" gear and flexible pricing.
Recently, Meraki has taken more of a proprietary relationship and widely criticized for managing firmware updates and increased pricing (some users have complained the mandatory updates break connectivity) and increased their pricing. Since the WiSP subscribes to the Meraki service and resells it end users like yourself, it invariably results in higher prices for your subscription.
Another point, is if you can find anyone at the ISP to answer and you're still intrigued about signing up, ask them specifically to explain their redundancy / high availability schema. It is a bit of a trick question since it isn't referred to as a "schema" but if they seem to embrace the term then it means the rep is shining you on or just trying to be overaccomodative.
Too many WiSP's are unsuitable for consumer usage because they have single points of failure to protect from outages, WiSP's and major providers including cellular companies often use the same gear but major providers provicde seamless service despite equipment outages that will take a smaller WiSP offline and you out of service.