It is better to have the extra ability (headroom) in the Sub, even if you rarely tap into it. Remember, you control the volume knob... it does not control you!
PB 2000 Pro
Don't forget, engage with you neighbors. Hopefully you are already friendly. Don't freak them out by telling them you are getting a bigger subwoofer, either. But if they do say something to you, ask if you can come over to hear, bring them a bottle of something nice.
In the end though, when you set up the sub, and you dial it in with your room correction, it's not going to be louder because its ported and/or larger. It will be calibrated the same way. Yes, the lower extension will be louder, but you can control that to some degree with DEQ and Dynamic Volume if you are on a Denon or Marantz, for example.
Frankly, I still think you should go with a PB 3000, but the 2000 Pro should do you nicely.