I would suggest that for HT, the Submersive would indeed be better than the Descent I. However, that is not to say that the Descent I is any slouch of a sub.
Have you measured your response with REW to see what is happening in your room? It may be that a little placement experimenting and/or a bit of eq'ing would help.
Have you measured your response with REW to see what is happening in your room? It may be that a little placement experimenting and/or a bit of eq'ing would help.