If you're anything like me, you're probably very used to the Mirage sound. I've had my M5si's for 11 years with no end in sight. The OM200 blended seamlesslessly and was instrumental in turning what was originally a near-full-range 2-channel system into a rip-snorting 7.1 ch. surround which still does music very well.
If I were you, I'd either add a second BPS150i to increase the slam factor or get the BPS400. I think the BPS400 will give you the slam and extension you're looking for while integrating well with your M5si's and remaining musical. If you like music, subwoofers that are only good for HT LFE are a drag. Not that I'm saying that the SVS 16-46 isn't musical--I don't know. But I think you can count on the Mirage subs being musical.
If I were you, I'd either add a second BPS150i to increase the slam factor or get the BPS400. I think the BPS400 will give you the slam and extension you're looking for while integrating well with your M5si's and remaining musical. If you like music, subwoofers that are only good for HT LFE are a drag. Not that I'm saying that the SVS 16-46 isn't musical--I don't know. But I think you can count on the Mirage subs being musical.