Sure, you could get theoretical speeds of about "20 Mbps down and 4 Mbps up from Comcast for $55 per month," but the service provided by Rucker's company, MonkeyBrains, is providing reliable and consistent speeds:
MonkeyBrains guarantees at least 10 Mbps symmetrical and most customers see 15-20 Mbps. Some customers see 25-30 Mbps with a good connection. According to [a company employee], this depends on the company's backhaul connection, which is in the process of being upgraded. Once that happens, he expects 30 Mbps+ connections will be common.
There are initial startup costs associated with the service—it costs about $250 to install the required antenna—but MonkeyBrains appears to be offering customers several free months of service to compensate for that cost.
The company is still small: It has "about 100 antennas, each of which may serve one or many customers—an average of 5-10 per antenna"—but it certainly appears to be off to a good start. Of course, the downside of a company like MonkeyBrains is that it provides such great—and cheap—service because it's sticking to a small area and focusing on those customers. This means that those of us who live outside of San Francisco are left hoping that someone will think to run a small WISP with a silly name in our areas too.