When hunting private yards digging smaller holes or plugs is better and the quicker you can pull finds also better. I've been detecting since the early 80s and one thing that I've noticed that is lacking on a lot of the newer detectors is good pinpointing systems and more reliance on the handheld probes. DD coils are less accurate than concentric coils for pinpointing. I've been using the XP Orx machine with a 9 inch HF coil but find I dig far larger holes than I did with my ancient Teknetics 8500 with a button pinpointer & (audio detuning) and concentric front. I realize the benefits of DD for field use but the drawbacks of DD outweigh the advantages for city detecting. Since XP does not produce a Concentric I may consider another machine like the older Tesoro Vacquero for more accuracy. Too bad Tesoro is now out of business.