I think I have the unit pretty much dialed in for MOST of the duty. it seems the LPF and indeed the sub works best at or near 120... and I do have the x over at 80z for now. it's SEAMLESS with the cornwalls in musical terms and the sound is natural and integrated... it's not standing out as a source and timbre seems good. I tried the LPF back and fourth and it just rolls on so smoothly at any point you use it, so I prefer close to 120.
one thing for sure, this sub is strong... it can easily overwhelm my system, I prefer it to be natural and smooth... I have found that position makes a BIG difference with this unit but for now, I am leaving it in the spot it is at basically for aesthetic reasons.
certainly $600 is a smoking price... I dont see how that is possible, but good on you mate, you WILL NOT be disappointed.