Over the weekend I visited my local hi-fi shop looking to purchase a REL subwoofer. While there he was excited for me to hear the YG Acoutsics Tor bookshelf speakers.
I have heard the big YG speakers at audio shows, yes they are amazing. Careful system matching is important or they will peal the wallpaper off the walls.
If you are still looking for a REL sub then Upscale Audio has the deal of the century until they run out.
REL G1 MkII Subwoofer - open box $4,395 (perfect condition) with full factory warranty and free shipping. List $5,500. This is the last time a new G1 MkII can be bought at this price because they are discontinued.
https://upscaleaudio.com/products/rel-g1-mk-ii-reference-subwoofer-piano-blackThe G1 MkII is between the REL Carbon Special and the $7,000 No. 31. Unfortunately, the G1 MkII has been discontinued, retail price used to be $5,500. I haven't seen a used G1 MkII for a while, the old original G1's show up all the time but they are long in the tooth and I am afraid the driver would have the same design flaw as the original G2 driver.
I am listening to the G1 MkII right now and words cannot describe how amazing it sounds on both music and Blu-ray movies. Streaming movies attenuate the lowest bass, uncompressed Blu-ray soundtracks really show off what this sub can do. Clear, deep, and explosive without a hint of compression. And loud, very loud like in the theater, almost scary, I had to turn it down.