The first Amazon review is detailed and in depth. https://www.amazon.com/dp/B01M260BAN/ref=cm_sw_r_cp_apa_M2jxAbKNGA71G

The typical value proposition of these large-capacity portable battery banks revolve around the "I hate dealing with gasoline/natural gas canisters, engine oil (required to run most gas generators, which are frequently sold without any), noise (gas generators are not quiet by design), and weight (DAE LIFT WEIGHTS!?!??!?)".

Having that said, I recognize the "leading lead acid competitor": it's the Goal Zero Yeti 1250, and having been on the market for quite some time, its performance characteristics are well-known. While browsing Amazon though I came across this non-SLA "gas generator". Notice the front panel with the 12V and USB outlets? That's a carbon copy of what was demoed on the Grengine, the difference is that the AC inverter outlets are on the side instead of being situated left of the panel.

*looks further down* Oh shit... Grengine Ultra Lite is a literal clone of what I just linked! This is an Alibaba resell! Then again, this is IGG, where reselling existing products is always a thing. Also the pricing for their Ultra Lite is $599 plus shipping. Er guys? These are already being sold on Amazon for just 400 bucks shipped!

Another thing about these battery-based "generators" is the user needs to get their feet dirty in solar panels and the like in order to get the most out of these heavy power banks. In other words, this isn't a battery pack, it's a long-term commitment into off-grid power and that $1450 price (for the full-size unit) is just a down-payment!

In a power blackout situation, I'd much rather have a gas generator instead.