This is certainly a very interesting read, as I am also contemplating whether to upgrade my 60csx to the 65s or perhaps the 66 or 67 series.
A lot of the discussion in this thread focus on the non removable li-ion battery of the 66, which is a major turn off for many, myself included.
But what I am curious about is, we have is a well established removable li-ion battery standard, such as 18650 cells (used in Tesla EVs), or 14500 cells (same size as AA, used in many higher quality flashlights), and many, many other variations. What's so hard, aside from greed, for manufacturers to start using these standard li-ion batteries? It promotes resource reuse, reduces e-waste, and are all around better option.
There are far too many electronics where every new iteration of the product wants to take a new battery format, or electronics with batteries that cannot be replaced, so the device is discarded because the battery has died, not because the device itself is faulty otherwise. This is completely unnecessary and utter waste of precious resource. Think back a few years, every phone wants its own custom charger, until the EU banned it.
Now I understand the cylinder format isn't optimal for certain electronics (such as your phone that needs to be flat and thin), and a different standard needs to be established. But for many devices such as Flashlights (which ironically is the one that embraces removable li-ion cells the most, aside from e-cigarettes), and GPS devices (which are currently taking AA battery), cells such as 14500, which are
IDENTICAL in size as AA, would be a no-brainer, easy migration for the manufactuer.
Li-ion IS better, no questions about that. But what we want is user replaceable li-ion batteries such as 14500. Perhaps one reason we don't see much devices using it is that people in the US, where Garmin is based, simply don't know they exist. Perhaps we should send Garmin product manager some 14500 flash lights
But li-ion batteries are good for 10+ years you say? Yes
IF manufacturer puts in some care in their product to ensure the non-removable battery will live a long and useful life. Otherwise (like 99.9% of products), the battery will die an untimely death because either it's been cooked at 100% the whole time (laptop always plugged in), or deeply discharged beyond repair (Kindle that can't be fully turned off). So no, batteries do not last 10 years, unless they are EV batteries in the car, because the manufacturer will be on the hook if that battery dies. Your electronic batteries are not, because the manufactures don't need to.
What about charger you say? Everyone who uses eneloop AA have a charger. If Garmin takes 18650 cells, we WILL get a charger. It's not something Garmin needs to be concerned about. It's a given, just like people using eneloop AAs are expected to have a charger.
Back to original topic.
How does the 65s with current firmware perform compare to say the 67 series?