I made the switch from Jetblue to Delta in 2017 and have no regrets. Granted, I was only at B6 for three years vs your six, but I still think it’s worth doing. Delta is leading the industry and is only getting better. Revenue, profits, growth, and the need to hire 8,000 pilots over the next 10 years will allow you to have a great career. Feel free to PM me if you have any questions.