As others said, don't think it worse than traditional carriers - potentially better. The big issue is around recovery. I had a flight cancelled on easyJet to Morocco a few years back during the busy holiday season due to weather at Gatwick. Problem was because they don't fly many flights there, next available seat was 2 weeks away. I had to cancel the trip entirely. I think that if I had been on a legacy carrier, the recovery options would have been better and I would have been able to make it down to Morocco for at least some of my trip.
Greg