I selected the Silvertron Elite because it gives me exactly what I want.
1) Makes 1 Gallon batches. I don't want to fool around making pints or quarts.
2) Puts me in control of production current. Others hide their production current. I use 2 milliamps on a 1 oz silver bar for smallest nano particles.
See this video for particle size: https://youtu.be/JujIburxXdE?t=74
3) Automatic shutoff
4) Makes batches at 20ppm or higher. I like the 30ppm setting.
5) All digital with memory to hold all settings even after power off.
6) comes with optional 1 oz silver bar. I don't want to screw around with silver wires. The anode (-) NEVER wears out, and a 1 oz silver bar will last a lifetime. The anode doesn't even need to be silver. You can use stainless steel. So polarity reversal is just more marketing hype.
7) I use an aquarium bubbler to stir the water. It is silly to go through all the expense & trouble for a magnetic stirrer. Just more marketing hype.