Cool effect. There are some EarthQuaker Devices boxes that do what this does in a way better way, with more options... But the vintage vibe from this guy is undeniable. Keep the fuzz low to hear the octave more.
Outside package might not be so sexy, but it's a complete recreation of Hendrix's original which was used on Purple Haze. Capable of producing a flavorful variety of fuzzed octave tones. Should add that it makes the strings thrum like they've got some current through them, really feels like your fingers are glued on! Worth tracking down.
Dunlop did a awesome job remaking this pedal. I would use it at the settings Jimi used but soon started experimenting. My settings might be whacked out to some so if you do have one "think outside" the box and have fun.