I took my Swift w/Scorchers out for a 10-mile loop through the city. Here are my thoughts:
These tires suck for city riding, where constant start-n-stops and yellow-light mad-dashes are king. I found myself out-of-the-saddle longer and pedaling harder to get from from zero-14mph than with my Comets. This is obviously NOT the ideal way to ride the city (unless you're aiming for a max calorie burn). I can best describe the standing acceleration of these tires as like I were towing a trailor. No exaggeration.
From 0-15mph, these tires feel like they're rolling through wet tar. That's the biggest problem with these tires: ~15mph is the average cruising speed in the city, given all the stops and starts, traffic-dodging, and sidewalk-surfing. An ideal city tire should blitz in this zone, and the Scorchers are absolute slugs.
Now on to the positives. Push these tires past the 15.5mph mark, and it's as if the trailor you've been towing was suddenly unhitched. I don't know what it is with these tires at higher speeds, if the centrifugal force dramatically alters the shape of the tire or what, but they really do move once you're in the tire's sweet-spot of 16mph. The same goes for sprinting. Sprint for a yellow light from 16.5mph, and the tires transform from slugs to "Scorchers". So long as I timed my sprint from 16.5mph, I was easily able to rocket through intersections in time to catch most red-lights (depending on distance).
I took delivery of a new set of Comet Kevlar 1.50s for my Dahon. I was surprised to see that these tires, in the same size as the Scorchers but higher weight, accelerated quicker and rolled faster at low speed on my Dahon than the Scorchers do on my Swift. They felt lighter on the road than the Scorchers, even though they are actually 10 grams heavier! For a fair comparison, I'm going to mount the 1.50 Comets on my Swift and go for the same 10-mile ride.