My flight experience is quite a bit different than most here on the forum. I fly out of Cleveland which is more expensive than the east coast, the west coast and other large cities. I am Delta loyal as I have Platinum status due to a combination of flights and my Amex card. I fly premium select or Delta one on the transatlantic portion and comfort plus on the domestic portion.
My personality drives me to purchase early, like 9 months early. So far, looking at the last 4 years this has really worked out for me. I have had flight changes, but I was able to change to an equal or better situation. I was upgraded to front of plane on a flight to Iceland, for example. Delta also allows you to cancel a flight for credit, so if a less expensive flight comes up I can cancel and rebook. Because I am flying twice a year on the same airline, I can always use the credit. But, I haven't had to do that because every flight I have booked has become more expensive over time. I also watch the upgrade prices weekly because occasionally the price will temporarily drop by a huge margin and I will jump on that.
From Cleveland in comfort plus, that would be a good price for those flights. I would book them. I am not familiar with the class products of those airlines.