I currently have a Blisstool V6 and ATX.
For relics-- it would depend on how high a minerals your soil possesses
In the super hot ATX deeper on lower and mid conductors
In medium to slightly hotter-- Blisstool will do very well on all but the real small
Relics-- it will find them, just not as deep as atx
ATX loves small low conductors --- even with 10x12 stock coil
Blisstool does have disc-- it works pretty good too
ATX-- iron rejection,,, works but as iron deepens not reliable, meaning on deeper iron you will get no rejection at all, or at least not textbook rejection.
EMI handling and stability on warm and hot ground--- could be the most stable unit currently made.
Does do a auto scan when iniated--- solid system
Not hard on batteries either--- tons better than TDI
I realize you asked about Blisstool V5---1 I would instead opt for V6 model, the
Reason for this is the V6 model has the capability to have faster recovery with option of ORE-- does separate better than V5, and believe it or not,,,not far back from Deus
Unit does operate at 8 kHz, with turbo boost running at 7.4 kHz
My Blisstool V6 will strike my 13" clad dime in my test garden with stock 11" coil.
In CW sites IMO a nice detector-- deep
I do have the newer released 7x9" coil
I don't have the 15" coil
Both ATX and Blisstool do have their places in the relic hunting world-- with the ATX the hotter the ground the more its performance capabilities will be seen.
Hope this helps