The stock cluster is really outdated in looks and function imo. It doesn't have a voltmeter or tach or even an oil pressure gauge. All it has is a speedometer, temperature, fuel, and odometer. The temperature gauge is mechanical as is the odometer and speedometer. The temperature gauge doesn't tell you the temperature, only a "H" or "C" indication. Some might like the "stock" look, but functionally it sucks. Mechanical gauges have so many issues even the speedo with the cable that often rattles, chatters, or breaks. Accuracy is very questionable with any mechanical instrument, imo.
The unavailable United Speedometer cluster attempts to address some of the deficiencies, but I don't know if they went electronic on everything. It still doesn't have a tach. And not all electronic gauges are equal...the old air core wire coil gauges had issues of their own and I think many suppliers still use them. I think Custom Rod Gauges suffered with them. The DD stepper motor gauges are by far the most accurate on the market, and that's what virtually all modern cars use. No car today has a mechanical speedo, tach, temperature gauge or oil pressure gauge. They're all outdated and unreliable.