Having owned both here are the pros and cons-
JL Audio
+Powerful, nice sounding bass with deep impact
-Cabinet resonance colored the midrange of my monitors- a deal breaker
-Difficult integration even with high level inputs and continuous phase control and REW measuring. after over a year the integration still was not perfect
-High level snap in connector difficult to install and somewhat loose.
REL
+Nice sounding bass, more subtle and very fast and musical. Plays flat to 20Hz in room.
+Solid cabinet with no resonance- midrange from monitors is perfect- no coloration.
+Extremely fast and easy to integrate, weeks vs. years.
+Level and crossover controls have "click steps" to document and adjust the settings.
+High level input cables are long and of good quality.
Keepers in my audiophile system.
JL Audio
+Powerful, nice sounding bass with deep impact
-Cabinet resonance colored the midrange of my monitors- a deal breaker
-Difficult integration even with high level inputs and continuous phase control and REW measuring. after over a year the integration still was not perfect
-High level snap in connector difficult to install and somewhat loose.
REL
+Nice sounding bass, more subtle and very fast and musical. Plays flat to 20Hz in room.
+Solid cabinet with no resonance- midrange from monitors is perfect- no coloration.
+Extremely fast and easy to integrate, weeks vs. years.
+Level and crossover controls have "click steps" to document and adjust the settings.
+High level input cables are long and of good quality.
Keepers in my audiophile system.