Did you end up buying the SilverLungs? If so how's it worked out?
I'm between another SilverGen or the SilverLungs. I like the larger diodes of the SilverLungs for faster production. The only thing that worries me about it is they don't use constant current or current limiting.
They say between the larger diodes, reversing current, and stirrer that the voltage is properly maintained anyway.
The only thing I don't like about the SilverGen is that on 20ppm there's lots of agglomeration and the brew tastes strongly metallic. However when the dial's closer to say 12 ppm that all goes away and it works very well.