I would rate it as b)impressed. It wont knock your socks off bass but it will give you a solid thump. The Cas Box does not extend out that much further than the stock one. I never hit it once when shifting, it never gets in the way at all. In fact I never even notice it there now. Unless your an RT/10 owner, you wont know that its not stock. Everyone that has seen it thinks it came from the factory that way. It was cast off an existing RT console and just pushed out a few inches to incorporate more volume. I have a Eclipse 10" sub in there being powered by an Rockford punch 150 pushing 300W to it. Its more than enough needed to drive it. Being that the sub is relatively close to you you will feel the vibrations when you crank it up. It gives you a sense of power from this thing. Remember this sub is enclosed and reverse mounted firing backwards so it is bouncing off of the rear then coming forward. The speaker grill is just for show, it is not vented. Wicked Cas ships the sub to you and they wrap it well. You can install it yourself or have any shop do it for you. They will build the sub to your specifications (close to stock as possible or added Bling) I opted for the stock look. Nazar at Wicked Cas is very helpful and will offer you as much advice as possible.
Overall, with this thing, your system is way ahead of the stock one. Even with the top off you can appreciate nice bass but then again my entire system is upgraded with 6.5's in the doors.
My advice in buying the sub box... Negotiate. I had a budget because my entire system was getting upgraded and its not like an RT/10 console sub gets sold there everyday. Just be fair. They are willing to work with you. (but you didn't hear this part from me if you know what I mean)