Had good meals at both places on my most recent trip through Albuquerque.
Dinner on the patio of Casa de Benavidez was more tranquil than the bustle of lunch at Perea's, but food is the top priority for me, and each place had strengths and weaknesses.
Casa de Benavidez's salsa is very good, fairly hot with more depth than many Albuquerque salsas. I didn't care for Perea's salsa-not a lot of flavor and too sour for my tastes. But Perea's guacamole was much better than Casa de Benavidez's(bland). Didn't care for the chile relleno(batter was too sweet) at CdB on my last visit, so I didn't steal a taste of my wife's this time, but I did sample her chile relleno at Perea's and thought it was one of the better examples that I've had in Alb. Red chile was hotter at CdB but better at Perea's; that combined with the fact that Perea's cheese enchilada had onion and CdB's didn't gave Perea's a clear edge on the cheese enchilada. Didn't have a tamale at CdB this time, but last time thought it was okay but not stellar. Perea's tamale was pretty decent but a little too salty(Los Cuates' tamale still reigns supreme in my book.) Carne adovada from CdB wasn't anything special, and the taco from Perea's I could have done without. The barbecue sauced rib that comes with some of CdB's combination plates is a nice change from the usual offerings and is dang tasty besides. Could have done without the rice from Perea's; had the option of rice or papitas at CdB and went with the papitas which I enjoyed. Had the option of whole beans or refrieds at Perea's and went with whole beans which were better than CdB's creamier(sort of between whole and refrieds in consistency)beans. Sopapillas were thinner at CdB, more bready at Perea's but about equal in quality.
Overall, I liked the food at Perea's better, and it has the advantage of being a few bucks cheaper per person than Casa de Benavidez. Liked 'em both though.