Albuquerque is a great example. A 250 W translator on Sandia Crest would get out as good as a C3 signal. Even Portland is a decent example, as 250 W from Silvan would get out pretty well. The 104.5 is back on from Skyline, which uses only 99 W but still really gets out. With nothing around on a clear frequency, a translator in Portland could be as good of a signal as either 93.1 or 96.3. The problem is that the dial is so packed that there are few if any viable frequencies. Take the 102.3 in Portland. I'm sure that would be a good signal if it weren't for KCRX 70 miles to the northwest and KEHK 100 miles to the south.In lots of smaller markets a well built translator can cover everything that matters. If you are in Valdosta, GA, or Albuquerque of Prescott, AZ or Lima, OH a translator... particularly on a tower over 500 feet, is quite viable. At around that point, they become comparable with a conforming Class A operation.
Remember, Urban One's Class A in DC with 2,900 watts at under 500 feet is 11th in revenue and 9th in 25-54 ratings. So a good translator in Roanoke or Fredricksburg or Harrisonburg or the like can do very well.