I think the only thing I like about this battery is the voltage. 4.1V is perfect for 3.3V LDOs. However, the battery voltage drops almost immediately and pretty linearly to about 2.7V and then falls off a cliff. The worst of it is how it collapses pretty quickly at cold temperatures and, if you were using the RFM69HW, it wouldn't take too many transmits to get the voltage down below the LDO dropout voltage.
I doubt that LiPo chargers would work with this battery, although I did NOT research that. It's just that the charging protocol is different than LiPo. The protocol is simple, but dependent on temperature and, IIRC, rate of discharge usage.
I'm also not impressed with the mAh rating.
They make a grand claim about battery life, but then advise that voltage falls off much faster after about 3000 charge cycles. At the rate this thing discharges, you'd have to charge it every day or more.
Net: These are my 'impressions', I did not do a thorough analysis and do not plan to, given these impressions.
Tom