I have the smaller Dynamo in my system and like it a lot. Its a very fast sub and very flexible in terms of features. Its small size makes for easy placement as well. For what its worth my local dealer pushed the less expensive Dynamo and Abyss over the Grotto which they did not care for as much. The Dynamo and Abyss are more flexible because they can be converted to either forward or downward firing. You could probably even do two Dynamos for the same price or less as the Grotto (as I recall). I also own the Depth(i) in my HT setup and although expensive, it is a true beast.
