tubedogg is asking about VGA adapters. VGA is analog.
ADC and DVI-I both include digital and analog signals. When connected to digital displays (such as Apple's or any DVI-D display), the digital pins are in use. When connected to analog displays (the CRT 17" Apple Studio Display with ADC or any DVI-A or VGA monitor) the analog pins are in use.
There's no quality difference between using ADC-VGA and DVI-VGA adapters.