Assuming even reasonable quality batteries the nature of such things is they should all be performing basically the same this early in their service life. Charged and discharged in the same way should give the same results no matter which one you pick out of the box. I think most of the variations can be explained by new users, limited experience and different perspectives. Hopefully they will average out over time.
The maker has said they expect several hours charging needed to replace the 1100 mAh that could be needed. Given he's also said they stayed below 500 mA out of respect for low power USB ports, this makes sense (the math works). Part of the rub is, the end of charge is not going to be at a full 500 mA (almost certainly, although it could for higher cost), but rather will 'taper off'. Still, a basic design should give at least half charge to a stone dead battery in a few hours. Just like the battery in your cell phone or laptop, you can do partial charges without penalty.
I'm not saying folks aren't having the experiences they are reporting, I'm just trying to fit it all together.
Against all that, 1100 mAh at 3.7 Volts is not a lot of power. That's less than twice what MFLB has available in a fully charged 2400 mAh battery (the factory one, not the high power 2700). 4 WH against 2.6. Nobody I know expects more than a few trenches from a pair of fresh charged batteries with MFLB, and it's about the most efficient vape out there. For another benchmark, that much energy would give you half an hour on PD or similar stem vapes (also well respected champs of being frugal with energy), enough to get it hot and do a few stems. Or it will run my HA for just over two minutes, not really enough to get it fully heated up even.
It may well turn out to be just the ticket for a few quick tokes on the sly, but as a 'daily driver' with any volume involved it's likely to fall short of the mark. I think the physics are against that.
OF