Sub users...

Thank you all for the great replies. While I have not researched subs, the JL Audio F113 is the one that has my attention. I would be using it to augment the lowest notes as you hint Rives, 30hz'ish and below.

I use a pair of Vandersteen 2Wq subs. Since these are fed from the amplifier speaker taps, they are indeed stereo subs. I have them positioned behind and outside the mains. I have no issues with imaging of low frequencies - images are stable in the range covered by the V2qs.

Did you consider a Wilson Watch Dog? Your speakers have a Q resonance bump around 80 Hz - you can see this on Soundstage measurement plots. This probably affects group delay also and the way the speaker integrates in the room. (speaker may resonate after the music stops up to an extra cycle or so due to this "tuning")

I have no experience adjusting to this speaker but it may be important to match this resonance to get smooth integration. For example, an SVS PB13 Ultra has three ports which you can block or unblock in order to adjust Q resonance (will affect group delay) and this might allow more seamless integration (you get four options of resonance and group delay by blocking none, 1, 2, or all three ports)

Perceptively, lower group delay will give a tighter bass sound kind of like a traditional Basie jazz drum set (just a hint of kick through room pressure). Higher group delay will give you a fuller rock kick drum sound in the bass.

Thanks for the info Shardone, but if I go with a sub it will not be with the Wilson's, but rather Ridge Street Sason's. My bad.

2- subs will be better in a 2ch system but one will still work well --I have the f113s and they are very good subs---since you have never owned any subs --you might just buy one and can always get another one later--you can experiment with diff xover points and find the one that is best for your system --you may surprise yourself that it will be higher than 30hz !!!