TS shows the 3.7hp unit for $850 and it appears to have the same specs as the 3.7hp that's $1200+ at Northern.
Given the fact that the TS 5hp weighs the same as the TS 3.7hp, my guess is the only difference is the 5hp rig runs the same pump as the 3.7hp, but at a higher speed.
The 5hp doesn't appear to be in stock at many stores. In my area, they have 15+ stores in a 75 mile radius and only one of them has the unit in stock. If not in stock, you'd have another $170 for delivery plus more if you need a lift gate.
FWIW, this "running HP" thing is the latest method of lying about horsepower on consumer grade air compressors. 15 amps is 3hp and not 3.7 and 20 amps is closer to 4hp than to 5. Also, if you want good life out of any single stage compressor, the cutout pressure should be set no higher than 135psi. Some of these Dewalts claim 175psi, I guess to impress the ignorant, but once any of this class of pumps goes above 130-135 the primary thing they're producing is heat and wear.
