i gained on the meter and it stayed stuck on just fine you have to clean and scratch surface for good results. i know several people who used it with gains. my old style dynomat did not work as well and came off.
i've seen and heard the 4000 watt model in action and it slammed 4 15 cv vmaxs. did a 147 at the dash on tl. at .5 daily never went into protect on anything, for the $ not terrible won't win any sq awards but will put some bump in the trunk.