The guys over on the Merkur forum are split. Most of them agree that it's extremely sensitive, too much actually, and that they limit performance because they pull so much timing (or whatever it is they do when they're set off). About half of them say just unplug it and run 93 octane and the other half say it's safe insurance and to leave it plugged in. I strictly run 93 octane anyways (sometimes 94 when it's available) so that's not a big deal for me.