Which detector is best for me?
The DD Series is geared towards enabling equipment operators to avoid hitting buried utilities within a defined area. The UI and functions are set up to support a grid search pattern.
The ULTRA series is geared towards tracing a utility from point A to point B. The UI helps the user stay on the path of a buried utility over distance.
The two use cases are not mutually exclusive: You can use a DD locator to trace utilities (the 230 and 130 have tracing modes) or an ULTRA locator to avoid them. It boils down to what you need to do most often.