REL Subwoofer: Speakon or RCA?

So, I'm currently connecting my Rogue Cronus Magnum amp to my REL Subwoofer using L/R RCA Cables. I'm leaving the amp via its variable output L/R RCA connection to the REL subwoofer L/R RCA inputs. I'm satisfied with the results. But now am wondering if, practically, I would hear an improvement (if so where? how?) if I switched to the Speakon cable for connection type. What do you think?
Speakon sounds significantly better.
Everything has a price for achieving a given effect. YMMV. 
I’ve had Rels for many years. Speakon sounds best to me for music.
I'm a REL dealer. Speakon is way better because the amp in the REL will emulate the character of the amp so the blending and seamlessness is much better.  It will sound like the amp in the REL is a Rogue.
I've  used Speakon stuff for years in pro audio so when I acquired a couple of RELs over the years I adopted their philosophy of the high level input for the reasons mentioned in audiobunker's post, and because I like Speakon Neutrik plugs...I make cables for the RELs from Canare Star Quad, AQ spades, and Speakon plugs...shrink tubes galore. I have to "stack" the spades on the posts of my amp, but that works fine as the main speaker's cables are bananas. Neutrik...made in Lichtenstein...