Nobody is ever going to say "what we sell is crap... run, run for your life to Circuit City"
If you were going to ask questions, you should have asked if the Bazooka or Infinity was better. Although, I bet they would have tried selling you the more expensive of the two anyway.
The bottom line is that you're going to get very flat bass out of those. The speaker is just too small. Get a decent 10" sub with a small amp... it might cost a few bucks more, but it's worth getting what you want the first time around.