replace my dual 1 with a dual 2?

[skeltron 0]

I originally bought a FI Q 12" dual 1 hoping to run it with a JL 1000.1v2 so I didn't really think much or care if it was dual 1 or dual 2. Unfortunately for my plan the 1000.1 would not of fit due to space restraints where I planned to mount it in my car. I instead went with a Sundown Audio SAX 1200Dv2 running the 12" Q @2ohm with ~700 watts. I find that the bass is adequate but when I look at the cone I can tell the excursion is not what it could be since im running it underpowered. Im wondering if I should sell the dual 1 I currently own and instead buy a dual 2 and run it at ~1200. What amount of DB sound difference would I be looking at? How much am I losing out exactly running it at less than half of the rated rms?