I did listen in mono when I built them, being as I built them one at a time. I listened to one speaker by itself for a few days and was actually surprised that not only could I could stand to listen in mono, but that it could actually sound good.
I'm not into home theater and I still prefer a more studio style of 2 channel listening, being that I can sit still for an entire album or 3, as a form of relaxation. Room integration ends up falling somewhat by the wayside and a lot of different speakers end up fitting the bill.
I do own 3 pairs of JBL speakers and have been a fan since the 70's. They always manage to march to the beat of their own drum, in spite of current trends, or being trendsetters in their own right.
If I were to buy a set of main JBL speakers new, I would tend to choose those that are rebuildable and that JBL would likely stock parts for, futuristically speaking.