Is Ravel a decent trombone

Ravel is not primarily known for making trombones; they are more recognized for their musical compositions and orchestration. If you meant a specific brand or model of Trombone associated with Ravel, it would be helpful to clarify. Generally, the quality of a trombone depends on its brand, model, and the player's preferences. If you are considering a specific trombone, it would be best to check reviews and try it out to see if it meets your needs.