I'm probably the member referred to who tried the @ease system with regular testing. It was OK, but I agree, the marketing of it is questionable. My conclusion on it from using it for a season was that it reminded me of my old SWCG system but without requiring the boost function after every soak. Once I started to trust it a bit more, I somewhat backed off from my obsessive daily testing routine. But... is that really worth the cost and limitations?
This season when I re-open the tub, I plan on going with the manual dichlor/bleach method as a comparison (been there, done that many years ago). I'm not yet convinced @ease is really a net positive compared to manual dosing, especially if one has the skills, interest, and ability to consistently keep up. Manual dosing is not rocket science, and sometimes it's kind of fun in a geeky way. SWCG can help automate some of it (but, somewhat like @ease, introduces its own fine print).
To the original question, @ease chlorine is a type of slow-dissolving solid chlorine as used in some toilet tank tablets (last I checked, the toilet tablets in question were more expensive per gram than @ease). It is actual chlorine. The silver cartridge seems to be the backup plan for when/if the chlorine levels crash at end of cartridge life. You still need to balance your water chemistry, test frequently, and adjust / replace the @ease cartridges periodically.
You can't chlorine-shock with @ease since it will lock up all your free chlorine above about .5 ppm into "the reserve." It was debated on this forum whether chorine locked up in "the @ease reserve" can become free-chlorine as FC levels fall below that .5 ppm. That seemed to be was indicated in my testing, but I don't understand the chemistry of how that could even work.