JL W7 line

Has anyone used these or heard these before? From what ive seen they are "supposedly" Some of the best subs on the market. I have been thinking about either buying a pair of the 8" w7's and mounting them in the rear of my car where the 6x8s are currently now.. That is IF the actual soundquality is up to par. Or id like to have a single 12w7 maybe even two in the trunk.... Please someone help me out with these here! Yes ive been here many times about subs... If you knew me you would know i like options! So please input!

Jeremy