Oh, I really like the Equinox. I think the stove is sexy as heck. Plant a thermo controlled cat in the top of that baby and it could be a real serious contender.
The Defiant was giving me 8 hours on the low end and 14+ on the high end for useable heat last year. I suspect I will have it consistently at 10 or more this season. The Defiant is 3.2 cu ft which is about the same as the IR.
I'm not saying you should look at the Defiant, but I am saying that you probably would benefit from a cat stove or two since burn times are your biggest priority.