No, it's not. The Sorex works much better in the air, but all we do search in the ground, right?
I was in a search trip with a friend, me with the Sorex and he with a Golden Mask 2 - an old model running at 8kHz.
We found a Turkish copper coin and we decided to test how deep the Sorex could go. We borrowed the coin at some 30 cm (12") and started to swipe. The Sorex indicated the coin with a very faltering signal changing the VDI from extreme left to extreme right - it usually do this for very rusty iron, but in this case it was a cooper coin. The Golden Mask 2 indicated the coin with a definitive non-ferrous signal. I changed frequencies on the Sorex (I was with the 3-frequency elliptic coil), changed the search mode, changed everything, but never had a better signal, a signal that I would dig...
After that day, I sold the Sorex and got a Golden Mask 1+ UK with a 12" Spider coil - much better for me. Not as deep as the Golden Mask 2, but very sensitive to gold and tiny objects. Very simple controls and lighting fast.
Oh, forgot that - the Sorex has a speedy mode to work within trash. That mode is really fast, but the depth is horrible, absolutely useless, except if you want to search coins that were spilled yesterday and are still on the grass.
And when I wrote the Sorex is no closer to my 1+ UK, I mean complex qualities, not the depth only. In some conditions, for example on a non-mineralized soils, the Sorex is as deep as the deepest machines on the market, but the game changes right after you change soil conditions. On mineralized soils you just cannot ground-balance the machine. It non-stop screams faulty signals and if you have a good target, you cannot distinguish it from the faulty ones.