I've had bad luck with a "high end" 80 gallon unit sold by Whirlpool and made in Tennessee by a major water heater manufacturer. Bought it at a box store. Two problems: The temperature control is a cheap potentiometer (it's a Ceramet ceramic pot for the geeks in the crowd). A lot of these pots get flakey after about 50 adjustments and don't like high humidity. The relays are undersized, and have stuck on. An online check shows this to be a common problem. There are also failures to an open. We have two of them (on one each geothermal heat pump) and the one that is cycled the most is giving trouble. Some day I'll just re-do the controller board for it.
In the old house, we had the standard hot water heater where you could replace the thermostat by the elements with a generic thermostat you could get at a hardware store. We were on well water, and all the comments on flushing are correct. The ball valve idea is great! Seems like very 3-4 years it needed a new thermostat.
So at this point, the old bimetallic thermostat looks better than the electronic control, just because the silly engineers that did the electronics control don't know enough about selecting the correct components (or their management knows too much about selecting parts that will barely make it past the warranty period).
With the geothermal heat pumps that also make hot water, the water is circulated through the heater via the drain valve in the bottom (and the hot water out at the top). In theory, this means that "the pot is always stirred" and sediment isn't a problem. In practice, well, time will tell. Surely someone in the construction trade wouldn't steer me wrong!
So I'd stay with the old fashion thermostat. Buy whatever has the most insulation around the tank. Replace the drain valve with a ball valve. Flush out the sediment annually.
Question for keegs: With regard to "well grounded", do you consider the ground provided by the AC power connection to be OK? And do your grounding concerns change if you have plastic/PEX vs. copper pipes?
Pete