DeKuma,
I just bought one and have yet to fish it so don't have any first hand experience. What I can tell you is out of the 3 most experienced guys (in our camp) that I met fishing in Canada last summer....guys who I considered very successful all swore by them. Their take was that although they were successful before buying the box they thought they were maybe 30% more successful after buying the box.

The motivation for me to buy one came after getting only one hit during the first 3 days of a summer trip to Nootka Sound while nearly everyone else was catching fish. Luckily several guys in our camp helped me out. One took me fishing in his boat.....using my rods, my setups, my bait, etc. and I hooked into a fish within 5 minutes of putting my gear in the water then had 6 more takedowns that day. Another guy confirmed I had a "hot" boat after testing the voltage coming off my downrigger wire.

The true test will come over the next year or so when I have a chance to put it to work.
JMS