Garmin inReach Explorer+, Bivystick Blue, or Zoleo??

What are your priorities, and how do you plan on using it.

Emergency only?
Volume of traffic?

There's no one-size-fits-all solution.

For pure and simple: "Get me outta here now!" the ResqLink is probably the cheapest solution. $200 and no usage fee. It's pretty much an EPIRB (sailor's rescue beacon) for use anywhere. You can even get one that floats. No messaging of any kind. Just an alert sent to SAR that you need rescuing.

But if you want messaging, then it gets a lot more complicated. And so does the money. Most of them require some kind of annual or monthly plan, and those dollars quickly exceed the cost of of the unit in two or three years.

And some (Like the Zoleo or Bivystick) require a phone as well--so you have to keep that in mind.   BivyStick has the least expensive usage plan:  $18/month, and you can turn it off any time you want for as long as you want.  Zoleo requires a $4/month fee just to keep it alive...then $20 a month for when you use it.  Most of the others are in the $15-20 a month for the smallest data plan.  

An additional factor that has always turned me off (bad pun) is that the technology evolves...and what you buy now may well be superseded by newer versions in a few years. I will never forget that the battery on my Magellan GPS died on my sailboat after about three years---and I was told there was no way to replace it---just buy a new GPS unit. Grrrrr.

I just got an InReach Mini and really like it from a functional. The initial price I can deal with but the subscription plan may be a gray cloud.

I wouldn't want anything that doesn't have a dedicated emergency button. Definitely don't like the solutions that require phone. I personally had the criteria of wanting to send occasional "I am here and OK" messages back to my wife when solo hiking.

I signed up in Oct and the annual fee for my "freedom" plan was about $35.

I have a eight year old ACR-GPS Personal Locator Beacon on its second battery. When hiking or biking it is on my person. Not the pack or saddle bag. I have only used it once, and it was not for me, for another hiker injured that I encountered on the trail. Assuring my registered contacts it was not me in the hours after took awhile.

After an avoidable SAR incident if I had a messenger, I bought a SPOTX just when they hit the market in summer of 2018. I have used it nearly every week to inform family or friends in my clutch about hikes, whereabouts, or change in plans. It is literally my second line. Both in the firmware and the mechanical keyboard it has been a disappointment. The SPOTX has in my use a dropped message score better than my smartphone. I may need to replace it before next summer. If I do, it will be with a full size inReach. I chose the SPOTX in '18 for the keyboard versus the GARMIN hunt and peck, better email, and direct EIN number. Despite the look, it is no Blackberry.

I was hoping on Space X Starlink in a hand held but I think that is a few more years away. I personally have no interest is smartphone connected devices. 

How long did the battery update take? I'm deciding whether to have the battery changed or upgrade to this year's model.

Yes, it's exactly that sort of nuanced information communication that shifted me on my replacement for my PLB to a more communication capable satellite messenger when it reached the end of it's FCC certified service life. The more information responders have the better everyone will be IMHO.