After a little more tuning I ended up with setting the Outlaw subtrim to -5, crossover at 80Hz and the SVS 2 notches down from halfway to one notch down from halfway. Phase set between 0 and 180.

This gets rid of the BOOMY sound of my old Klipsch KSW-12 SUB and replaces it with clean but very low bass (that's the point right?

Girlfriend who couldn't care less about the set-up said "Where did the rumble go?" then some deeeep base came out of nowhere and she said "Ahhh, that's how it's supposed to sound then?" Funny stuff.

This setting lacks that punch I'm used to with my old sub, so it will take some time to adjust. Still more tweaking to do!