The Ace is like the Prizm you have/had but it has a more delayed recovery time,I prefer the Prizm's tones (I didn't like the belltones on the Ace), pinpointing is better with the Prizm although it is easy to pinpoint with the Ace once you get the hang of it, in my opinion it would be a step down from your Prizm IV. Steve.No, i have/had a prizm IV, just wondering what the ace 250 is like.