I just purchased an SMS-1 & Final Sound sub combo. Although I'm not using the Final Sound subs in the same theater.

Paired the SMS-1 up to my LFM-1 EX and LFM-compact 10" subs.

Works really well when you take the time to set it up fully. I used a few other pieces of equipment to measure standing waves in the room. The SMS-1 has certainly helped and it's great to have a sub controller off the AVR.