This is just my opinion....I purchased an ACE 250 three years ago. I found some buttons and old Connecticut Copper's with it but it was very limited rejecting hot rocks. Spent quite a bit of time digging nails and other junk. I sort of gave up on the hobby; and then accidently ran the detector over in my car. It still worked, but a bit wobbly. This spring my husband got me a DFX for our anniversary. Going over the same area I did with my ACE 250 I found a 1777 Military button. The DFX paid for itself. I wouldn't have had paid that much for a detector, but I'm sure glad he did.