yes. I would keep the L7. you will regret either trade because they will not produce the same sound you are used to. Different subs and boxes have different peaks so the songs you know and enjoy will sound like ass if you make either of those trades.
The MTX9500 with less surface area and the same power will be less loud.
The CVRs as a pair will not be louder because their is no way to wire them so they will receive the full power of the amplifier.. any way you try, they will only get half power.
One CVR by itself in the right enclosure could be louder but again, you will still have different peaks and songs you love won't sound as good.