Dedicated 20 amp circuit - Electrician laughed!

Millercarbon.  Multiple ground rods must be installed close to each other and be daisy-chained.  Different soil consists will produce different ground potentials.  This can have very bad implications... Problem is that many different locales have very different grounding capabilities.  Sometimes ground rods are welded end to end to reach down far enough to reach moisture that will provide a good ground. Corrosion enters into the issue.

My double ground rods are driven 4” apart close to a roof downspout to insure a “good” ground.  Even so, there is an extension of our drip system that provides constant moisture for a stable ground.

piaudiol - you're absolutely right

All single grounding electrodes must have a resistance to earth of 25 ohms or less - if not, you must add additional electrodes and "daisy chain" them together.

I ran a quad shielded 10 wire directly to the panel on a 20 amp circuit. I installed another grounding rod attached to the original grounding rod, about 5 feet apart. I used an AQ plug in the wall that has a very tight connection. The voltage drop is less than 5 percent at the plug. Throughout the rest of my old ranch house, I have endeavored to rewire with quality parts, such as a $5 dollar plug vs a 79 cent plug. If I could start with a clean slate in a new house, I would be careful to select the best parts available. There are panels that have thicker copper bus bars. I would say that the more robust your electrical system is, the likelihood of better performance with whatever you're plugging into it is ensured. When I ran the dedicated circuit for the main system, I believe that things got quieter. I do have things plugged into a Furman Elite 20PFI, mostly for protection from spikes. If you don't want to run a dedicated circuit, then I would at least install a quality plug and tighten up connections at the panel. Electrical systems require maintenance just like anything else. I am seeing million dollar homes getting built in my neighborhood as older homes get torn down. These homes likely have the cheapest parts installed that is required to meet code. When the "amazing" builder gets estimates from three electrical contractors, he doesn't select the best man for the job, he selects the cheapest. Modern electrical systems are designed to last about 10 years.  

Listen to him. The man is saving you a lot of potentially wasted money.

LOL.....   after so many miles of garbage quality transmission lines and grunge being put into the lines you think cleaning up the last few feet is going to make a difference?  REALLY?