MoFi or Harbeth (used)

You simply must go listen to both pairs of speakers and let your ears be your guide.  Period!!!

Harbeth by a country mile.

@soix  All point source speakers are relatively poor off axis as the volume the speaker produces drops off rapidly with distance including the Ohms. The best kind of speaker for off axis listening is a line source. Because the volume drops of much slower with distance you can still hear the far speaker clearly. A full range line source has to run from floor to ceiling, anything shorter becomes a point source at low frequencies. As an example Magnepans become point sources at about 200 Hz. Above that they are line source and clearly audible off axis. The only full range line sources I am aware of are the 8 and 9 foot Sound Labs ESLs. 

I have both SourcePoint 8 & 10 and I’m super impressed.  The imaging is astonishing and it’s a very natural sound.  I’m a big fan of coincentric drivers and have owned many Tannoy and KEF models.  This is a winning combination without the brightness that many speakers these days suffer from.  I have never owned Harbeth, but they have always sounded great at the shows.  SourcePoint speakers completely disappear in my room, and that’s what I love in a speaker.

Given your room size, the Pointsource 10 will deliver more pressurization than that model Harbeth, whatever its other virtues. It comes down to your priorities.  Based on my listening experience, the Pointsource 10 is balanced to be neutral, and from all I hear about Harbeth, they are balanced to be “warm”.  But the 7ES is a smaller box and an 8” woofer, 86 dB vs 91 dB.  That is a big difference.  Your stated music preferences tilt towards greater cone area and sensitivity being advantages.

Source point in a heartbeat. Will get your foot tapping and heart pumping. Harbeth will put you to sleep 😴