Hello gentlemen,
REL started out in Wales and like Dynaudio, another European speaker manufacturer, REL focused on a typical European set up (smaller room, brick building, 220 V electricity, etc...) It makes sense for an audiophile who has a small-mid size listening area to go with REL where REL power subwoofers would do best.
I have heard of JL Audio years before they entered the home audio market and indeed it is a reputable company. But keep in mind that unlike REL, JL Audio started out as a car audio company based in Florida and its design philosophy is totally different than that of REL. Since JL Audio focused entirely on American market where the majority of the market demands are bigger means better. It makes perfect sense if you have a listening area the size of Brazil to use JL Audio powered subwoofers rather than REL.
A million dollar system would not sound great in my man cave (I am a dirt poor accountant who could only afford Hsu or Outlaw power subs or TOTEM if I am lucky to come across a great deal on audio) but of course this system will definitely sound great in Mr. Oneobgyn's house. A hometheater system that costs less than $20K will not do his listening area justice.
REL is a good company and it still has many serious audiophile followers. However, REL is no longer the little mom-and-pop company like TOTEM or maybe JL Audio (I am not too sure because I assume JL Audio is) so the quality of REL products have been somewhat decreased.
Kind regards,