I quickly "walk" the Garrett into the target's real location by simply pressing the button(detune). It's easy. I have to do the same with the TRX to some degree. All in all, I personally find that the Garrett is faster in actual retrieval with side detection...out of the hole in the pile of dirt for sure. That little flashlight beam area on the TRX's tip is tedious.
As far as the depth being close to twice of the Garretts, that's true to a degree. Thing is, when it's "made" to get that extreme range, you'll most times find it goes unstable anywhere, even near simple ground level, and then has to be retuned, so any double-depth becomes only an inch & half extra tops. That's still very good, and why I run my TRX on the highest setting.
If the TRX had an added option for even partial side down the wand, it'd be my absolute standalone pinpointer. I carry both of these pointers in the field, best of both worlds.
Retrieval TIME is my pimary desire. The Garretts get it done faster for me. Detune is a key feature of both the TRX and Garrett. I'm just not the patient type using the TRX's flaslight beam for the entire dig.