The combined results of the six most recent NP-BX1 batteries for my Sony HDR-AS30V helmet camera:

One might reasonably conclude all six came from the same factory; the STK B battery looks like a dud. The two replacement batteries from STK performed slightly better than the first pair.
The Wasabi and SterlingTEK batteries all carry a 1600 mA·h rating that’s far in excess of their actual 1000-ish mA·h performance. If they were advertised as 1.0 A·h batteries, they’d meet their specifications (for small values of “meet”), but nobody would buy a second-tier battery with less capacity than the Sony OEM battery’s 1.24 A·h.
If you rummage around in previous posts, I did verify that battery capacity does increase with decreasing test current, but definitely not by the 60% needed to reach 1600 mA·h.
Because most devices these days operate at constant power from a boost supply, presenting the results against a watt·hour scale would make sense:

That doesn’t change the overall rankings, such as they are, but does include the effect of higher terminal voltage.
The claimed specifications:
- Sony OEM – 4.5 W·h
- Wasabi – 5.7 W·h
- STK – 5.9 W·h
The Sony battery actually performed about as advertised, but the others fall short on this scale, too.
They should survive for hour-long rides with the GPS tracker turned off, which is about as much as I want to ride at once. I’ll eventually autopsy the STK B battery, which won’t last all that long.
Credit where credit is due: after I sent the first test results to STK, they sent a pair of replacement batteries and, based on the second test results, refunded the entire purchase price. I’m reluctant to give a five-star rating for customer service, because shipping mis-advertised products should carry a zero-star rating.