Fishhound,
From what I understand the Ace 250 works well here. We all digs tons of junk and it really depends on the sites you are hunting. If you are in an area that is 60+ years old you may want to dig as much as possible as there are many valuable items that would be missed by only digging coin signals. I will tell you that I have dug two territorial trade tokens and they both rang in the trash range. I mention these two tokens in particular because they are valuable but they are shaped like junk, wafer thin with stamped lettering.
I am biased toward the minelab detectors with multiple frequencies and ground tracking automatic ground balancing. If you hunt near the Great Salt lake on any alkali soil or sand the area is highly mineralized and the minelab is the only detector that will function under those conditions. I am not sure how often you have the opportunity to hunt there, but I have only done it once. Some people may dispute that claim, but I know from hunting Saltaire that there were honestly no other machines that functioned there.
Keep at it with your ace. I know that when I first started I thought I would never get any good and there were only pennies to be found.
HH