So far, the Delta out of the above mentioned is the best way to go, but it still doesn't have manual ground balance. That's fine if you just want mediocre performance in any bad soil, but not if the soil gets rough. The Aces are annoying as all heck with their dated audio "bong, bong" sound lag from 1980's phase-shift delay technology. I know, I owned one. They DO NOT DO WELL on far-Western (or) high Fe soils, and by now most experienced detectorists know that. .
The Fisher F5 is a good way to go. It costs $495 but it's also the same thing as a Teknetics Omega 8000 at $599, with more toys but in a different, more adjustable package if you care to fine-tune it. It's just set up differently as an analog. Both are powerhouses! They can even do pretty well at salt water beaches if you ever get near one. The above other ones won't match the F5, including the MXT, although the M6 gets close to the F5 in these cases. The M6 is a bit noisier though, as many Whites often are.
I see that you bought the Cibola. It's a nice little unit, extremely popular. You will like it, especially since it runs so very smoothly and quietly. HH
Larry