Hello Dan,
I use the Blisstool V5 model, And can honesty say it does detect deep out in open ground (fields/orchards) and such.
Here's an example, Recently picked up a deep signal and called my hunting buddy over to check the signal with his Deus. Deus sens was 90 so it was pretty high, Tried different kHz while scanning the Deus coil over the signal and the Deus would not give an audio signal but did give a small visual clip on the upper right horseshoe, Not a signal to dig and would most likely have been passed by most Deus users.
Dug a deep plug and sure enough at the bottom was a small dime size piece of low conductive trash, The V5 hit that deep signal with ease loud and clear. However, For me the v5 is for certain hunting conditions out in open areas like farm land and such were old settlements of long ago are hidden showing no signs of ever being there, It's here out in these areas my Blisstool v5 surpasses my other top end detectors.
Normally, Due to the mineralization in my area can only run gain at it's lowest setting but can run Boost on. Even with these settings the v5 punches down deep deeper than my top end VLF, The only other detector that can punch down as deep or even deeper at times is my ATX PI. We have some mineralization that do effect VLF, The V5 is one of the few detectors that does well in my area even with the lowest Gain setting but with boost on this gives the v5 that added punch.
Blisstoll is not for everyone, One needs patience, persistence and eventually they will see the advantage with using the v5.
Paul (Ca)