Considering all the different littlebox/tinybox configurations, and all the variables involved, this might be an instance where theory trumps practice.
From my own experience, I have never run down my littlebox nor run it long enough for the low battery indicator to come on. For most of its life though, I have run it at the low voltage setting (~20v) rather than at 48v since my Milabs and my Beyers are spec'd for 12-48v operation. At the low 20v setting, it should be good for 20-24hours of operation, so no shock that I haven't run it down. I've more recently been running it at 48v, which should be good for 10+ hours, and have never run it down.
All that said, if you want to make sense of any of this, you need to know the full details from the reporting user.
In my case, I have an early 1st gen LB that allowed user-specified inamps, and I requested Burr-Brown chips that I think draw 3-4ma per channel, whereas the latest gen LB's use a standard amp (forgot what it is Jon is using now) that draws something like 1ma/channel, maybe less.
I run mics (depending on which I use) that draw either 4.6ma/mic or 4ma/mic. Other mics might only draw ~2.5ma/mic. So between my mics and non-standard amps, my littlebox might be drawing twice what another person's littlebox is drawing, and I should expect half the battery life.
I also got the first ever li-ion put into a littlebox (requested Jon to do it for me, and he made it an option). IIRC, I have a 2000ma-hr battery in my littlebox, whereas the last/latest littleboxes use a 1400ma-hr battery I believe. So on that basis, my LB should provide ~40% better life compared to a typical li-ion LB, if of course it wasn't configured with inamps that draw 3x the current of the standard inamps.
Confusing enough yet?