REL T-9 or S/2

I have reached a point in building my system that has finally just makes me smile. However, I feel as though I am missing just one small piece and that is bass.
My system consists of:
Baetis Revolution Music Server
Berkeley Alpha DAC 2
Red Dragon M500MKII's
Focal Chorus 836w's
Snake River BoomSlang BNC/BNC digital cable
AudioQuest Water XLR's
Analysis Plus Solo Crystal Oval 8
I am obviously not looking for HT bass but that last little emphasis to sure up the bass.
I have heard a few different subs including REL.I like the theory they are using for the Hi Level wiring, which comes directly off the amp feeding the mains.
At the price points I am able to purchase these subs, there is a significant price difference.
I will be adding a pair, so it would be approximately $1000.
I was hoping that someone was able to do an A/B comparison.
All thought appreciated.