I don't see anything there that says the Challenger wins on the street. Beyond that, the price isn't that interesting considering the tested Mustang is loaded and the Scat-Pack has no added options (unlike the Mustang, I believe the manual is actually an added-cost option on the Challenger). The base Mustang GT price is more than $5,000 less than the Scat-Pack.
I will admit that Ford is slipping behind with respect to transmissions with more gears, especially since their new transmissions seem to be a couple of years away still.
Looking at the 0 - 60 time as a "predictor" for "street light to street light" performance
2013 Mustang GT Premium Convertible
Candy Apple Red, Auto, FRPP Tune, GT500 Axlebacks, KONI Yellow Sport (adjustable dampers), FRPP Front and Rear swaybars, Custom Removable 4 Point Roll-Bar, BOSS 302 Low Expansion Brake Lines, Roush side splitters, GT500 spoiler, Redline Tuning hood struts,18" Ford Chromed Aluminum Wheels (9R3Z-1K007-A), Michelin Pilot Super Sports - 235X50X18
2011 Mustang V6 Premium Convertible - Gone