You'll get more responses for the Ace simply because it has been around for longer. In my experience with BOTH of them, they performed similarly, but the White's seemed to go deeper.
The 250 is a slight upgrade from the 150,and is a closer comparison with the coinmaster.
i own the ace 150 and 250 with the 350 on the way i would highly recommend the 150 if your new 250 if u want a "pinpointer" attached but i wouldn't bet my life on the pinpointer pretty inaccurate