I used the PDX 4.150 and really liked it. It is VERY efficient as stated. A forum member on
DIYMA said he had the amp as well and then went with the JL and did notice a drastic change and said it sounded cleaner. He then went with an Audison amp and said that was even more cleaner. This guy does know his SQ to great detail, does his own tuning, and has a great sounding system, etc. I personally have no experience with the JL, and I wouldn't quite say I have SQ ears like some other guys, but I was pleased with the PDX...just thought I'd share the info with ya.