Greg, I have been a lover of 15s forever, in fact , 2-1x15s is still my rehearsal rig.
That said, live, I have been using an Acme 2x10 cab for a few years. Both bands I play in
one cab is more than enough. My dream rig would be two of these in a vertical stack, but,
as I said, only one is necessary. These cabs put out big sound, comparable to an 18, in my opinion.
The only drawback to them is that you need to hit them with a lot of wattage. I use either a 600 watt or 900
watt head, not to get loud, just they are intentionally inefficient.
The irony here is, the designer, Andy Lewis, is a drummer.