Flew Vanguard once from MSP to MDW. Both legs of the flight were VERY late. Into MDW, I had a 7am flight - usually the most on time flight you can get - well they checked us all in and then didn't tell us until 6:30 that we wouldn't be leaving until 9AM (!) because the flight crew didn't have enough downtime out of the air. They couldn't tell me this when I checked in at 5am! Then on the return leg, the plane that was taking us from MDW to MSP was 90 minutes late arriving so we didn't leave until over 2 hours after schedule.
They are notorious for being late, I found out from a passenger flying Vanguard to MSP only because he had 12 free tickets on them for when they stranded him for 12 hours. So if you like to keep to a schedule, I'd go with some other airline and pay for puctuali9ty.