My search didn't reveal a recent discussion of whats currently available in PLB's.

W&W shows two...
Kannad XS-4
Fast find 220 PLB

What are the advantages of each?

Are there other better ones?

Seems like the biggest issue is that when the battery life is up you essentially have to buy a new one as it costs almost as much to replace the battery as a new PLB costs. Are there better options?

Brian