GC2 batteries: help me pick power supply for maintenance

Are there links to these recommended gizmo genius chargers? I would love to peruse through the hyperbole and see if progress has been made in the last 5-years. If somone could post a column of links below somewhere I will save the list to disk. Internet is far too slow here for much searching on my part.

And again, I state emphatically there is a world of difference between same batteries used by a weekend warrior versus a hermit. One stress tests the battery
The other bores it to death...