The Old Karnak didn't have doors IIRC, but the new, HTL, one does

Anyhow, after reading some other comments, I think the key to using the Ravana isn't just to not have it use its main beams, but to present it properly. It's the framework surrounding the usage of the Ravana that is cliché - there aren't enough Shivan destroyer models around to really avoid using the Ravana that way (nor can the Ravana be used effectively in any other way, much - I still don't think it's a good idea for a Ravana to play anti-fighter role, as it's going to wind up with its beams disabled, and when it gets attacked by say, a cruiser even, it's pretty ****ed. Stupid idea, if you ask me).
As long as there's more to do than just "Destroy front beams, then proceed to ignore.", or if the atmosphere is right for it, I think it's OK. It's the dryness of the mission design that really hurts it, not the role. The Ravana's role is pretty dead set. It's built for offensive beam strikes, and that's all it can do.