It really depends a lot on placement and the production of the album. The more you can get them out from the wall, the bass gets better. Some albums (Uriah Heep, Magician's Birthday and Demons and Wizards) for example, sound really thin. A subwoofer can add some bottom to these thin recordings. A newer production, Opeth's album Heritage has a nice thick bass that doesn't need much supplement. My rig has no tone controls or EQ of any kind so I have to take the production of albums at face value.
Overall, the Maggie's alone wouldn't suit most typical rock listeners. I've found that your average rock listener likes to feel pounding bass. They won't really do that, but what they do is clean as hell. You have to hear them to know what i'm saying.
