Subwoofers: Ported or sealed?

For music, I much prefer low Q sealed. The roll-off much better matches the room gain so flatter to start with,

This is a subject I don't think most audiophiles understand.  You have no idea what in-room bass response will be until you get the speaker in place.  In many cases the problem is too much bass and exaggerrated room modes.

you don't need additional subsonic high pass filtering.

Well, a subsonic filter can protect your speakers and reduce power demand, but sure.

Sealed and ported have similar efficiencies in the pass-band. Ported will go down lower.

All my experience and measurements say that the bigger issue is the amount of bass in a room. If you want to plumb the depths of bass with a sub you have to be careful of the placement and use appropriate room treatments and/or EQ as/if needed.

Smaller, sealed subs tend to leave the sleeping dragons alone. They don’t excite the room modes and therefore won’t ruin the sound. It is also true that below the tuning frequency, ported subs climb in distortion due to increasing exertion. They may also be significantly larger than the sealed counter parts.

I use a Hsu sub which has optional plugs. Whether I use them or not has to do with the in-room response.

Having said all of that, if we aren't talking about subs, I built a sealed center channel specifically because I knew I wanted to use it with a subwoofer, and crossing it over at 80 Hz or so would mean I'd get a lot of dynamic range and lower distortion in that configuration than I would otherwise.