In my opinion, a White’s TRX pinpointer isn’t usable enough as, for instance, a Garrett Pro-Pointer is. The White’s TRX doesn’t complete a full 360° detection area – providing a tip only detection. There are also other opinions, though… Watch the video: White’s TRX vs Garrett Pro-Pointer.
All about a Garrett Pro-Pointer is collected here (videos, comparisons, tests). Plus, there is additional information (specs, features, and more) on Knowledgebase pages. All about a White’s TRX pinpointer is here and here.