I don’t know if your class happened already, but I did it in January and it was fun since it was free, but nothing that special (though the instructor was great and it was nice to start the day with some stretching). A little early, but since I was coming from the east coast it didn’t feel as bad.
Ours was taught by the spa’s lead fitness instructor who also taught the $100+ runDisney yoga class in front of the castle the day before. She has great energy and the class was accessible for all levels. They provide a mat to borrow and also give you a water bottle, snack bar, and hand warmers if it’s cold.
The location isn’t anything special, like some of the exercise classes they have in the park.
Definitely a fun free activity if you don’t mind waking up early for it!