Man, thanks for all of the great replies, fellas! It looks like I'm either going to go with a set of the CDT EF's or the A/D/S 346 cs sets.
The MB Quart set that I have now is awesome (Q 218.13CX), but I believe that one of my midbass woofers is either blown or is on the verge of blowing. I can hear a distinct rattle/buzzing noise coming from the passenger side speaker, and I definitely don't hear it coming from the driver's side door. That really sucks, too, because they really crank being run from a JL 300/4.
If I get the A/D/S or the CDT EF set, I'll be running those from an oldschool Soundstream 644s 4 channel amp.....if you're looking for a slightly used JL 300/4, I'll have one available for sale soon!