I had a terrible experience. I purchased a pretty expensive business class ticket because i had to work 16 hours straight before traveling HYD-dxb-Sof. My first flight I was told aircraft was swapped at last moment and the plane has only economy seating “but I promise you there will still be lie flat for dxb to sofia”. But arriving at the gate in Dubai my seat is changed and dxb-sofia has the pretty poor recliner seats. 2 out of 2 aircraft substitutions is pretty unacceptable. Even a full refund wouldn’t make me happy because I can’t get the night of sleep back.