Dude Going from your w3vs's to 10" CVRs would be a downgrade in SQ and about equal for output. JL has won national consumer electronics shows with all of theier subs. 8w7 10w7 10w6v2 12w6v2 13w1v2 12w7 and 15w3. Kicker has had some sucess in national SPL events but JL has some w7 setups that near as loud and have some SQ. JL also won the award for the best sounding car at CES 2005 but some smaller companies just couldnt afford to comptete they may sound better than JL. Ok there are better companies than JL for your money. UIm sure many people on the net can tell you that. But with what you have , one 10w3v2, if you want more bass just get another and have someone build you the right box. If you want it louder, Kickers New CVX subwoofers have been getting known for SQ. There are also other companies that you could replace your JL with a pair of but in your positon One more w3v2 would fit the bill with a proper enclosure built. Also uprgading your deck or front stage might suit you. Or your avaiable power and wiring and perhaps a BIG 3 with 4 gauge. Or try dynamat. Check ebay, for trusted stores that are known not to sell refurbs. Or find some high quality amplifiers used or new in the forum classifieds. Good luck im sure some guys have better advice than i do.
im a kicker guy myself but for pure SQ JL. having done a few installs w both the cvrs have good SQ as well as output plus being 1/2 the price, depends on your wallet and preference.