I would love to see this color-coded with average house/apartment prices --- to see if each arc is equitable or if you can see a pattern ( +10% by the water, etc).
It's not 100% accurate, but it gives you a rough estimate of time to the Hub vs. rent. In general, the biggest selling point for Boston apartment seekers is proximity to the T and time to commute to the the Financial District (near Goverment Center). Areas near colleges (BU, MIT, Havard, Northeastern) are also high rent because college students eat up most of the housing.
As an active apartment seeker in Boston, the original heatmap data source is generally pretty accurate: http://www.jefftk.com/apartment_prices/index