I have a Silver UMax.Had a chance to swap use with a person that uses an Ace. Silver goes deeper on coins, I didn't care for the Ace. The person wanted to trade. However, from what I understand is that the Ace is starved powerwise at the coils. There may be some mods that could give some extra three to four inches on a coin. May just pick up a used one and find someone to do the work for me. In the mean, stock vs stock, I like the Silver. Saw one new in box at Treasure Depot Classifieds for $190.00 postage paid..Just my two cents worth, and an arguement can be made in the other direction...,cordially NAD