I've been really happy with our salt based chlorinator system. Super easy.
Never heard of the copper system but a quick search finds a few articles on the working of this device. Interesting device. Look like it has the usual plus and minus of any non-traditional setup. Here is a negative article for 'balance'.
https://homeguides.sfgate.com/disadvantages-pool-ionization-96794.html

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1985 300D
The rest:
1957 MGA (comatose)
1965 Falcon (sleeping)
1966 E-100 (rust test in progress)
1976 Ford 3400 D Tractor (workhorse)
1978 Mercury Zephyer (5L playtoy)
1995 Isuzu NPR D (fetcher)
1998 Subaru Legacy (Spare)
2000 Toyota Sienna (School bus)
2008 Toyota Prius (Commuter)