We sailed summit in March this year and last year in royal suite, suite restaurant Luminae was great , definitely prefer M class to E class for dining room. Indoor retreat was also fantastic, service couldn’t be better. Outside retreat is pitiful no bar or pool and no elevator to get there . We are booked again on Summit next year since that hosts our music charter that we love . For overall experience I agree with others who mentioned MSc yacht club which I have booked for late this year. Only celebrity E class can match yacht club since they have outdoor pool bar etc.