Give me a WN 737 over a Delta CRJ every single day of the year. For a short-haul traveler that doesn't care for international/Hawaii flights, WN offers a great FFP. If I was going to Chicago twice a week, I'd probably go with WN - an upgrade isn't a huge deal on a 45 minute flight, and two round-trips a week would get me about 8 free tickets a year, plus a companion pass which is worth its weight in gold if you have someone who travels with you a lot.