El, I believe my 705 does have more depth capabilities and is more sensitive than the X-70. Without knowing the technical reason, I would have to surmise it has to do with the upgraded software. I think the enhanced software also allows me to sweep the 705 a bit slower, while remaining stable. I don't notice the standard GB being anymore precise than the X-70. But I do like the ability to offset the Tracking either positive or negative. Something else I have noticed with the 705, compared to the X-70, is the audio report on deep targets. Like just about every other single frequency VLF detector out there, the X-70 seemed to be a "go or no-go" on deep targets. In other words, it would either it hit them with a good audio report or they'd be too deep to hear them at all. With the 705 in multiple tone, all metal mode (which I typically use for both the X-70 and 705), I am able to hear a slight "echo" audio or "whisper" on the deepest of the deep. Again, I would attribute that to the software upgrade. The X-70 is a great detector and it hunts darn deep. But the 705 has been able to go back to some of the sites I've hit with a lot of different detectors, and sniff out some pretty deep coins. JMHO HH Randy