Just added the Rel T7x to my LRS pluses. I drive these with a Rogue Sphinx3. I was able to compare the SVS with the REL side by side in a controlled switchable environment. The test song I use for bass is "Sixteen Tons" by Geoff Castellucci.
My experience would define the SVS as a rock and roll speaker, in the sound room environment it had tremendous bass, yet lots of overhang that muddy the accuracy. The Rel was as stable as the rock of Gibraltar.
My take is if you are listening to stereo, that is simply compilations on the left and right side. They are different, so technically you need two woofers. I bought one, because that is all I could afford $990, this new hi-fi biz, is far more expensive than when I was in the business 50 years ago. And pricing is not relative to the years that have passed. There was no such thing as a $100,000 turntable, cartridge back then. I was a hi end dealer, Mac, Magnapan, Yamaha, Advent etc. I had to retire to live a real life (kids, family, college). Loved hi fi then, love it now. Just cant afford it now either. Two woofers, starting at a T7 like product and up.