K. Do any of you have it or have tried it? I am thinking of getting it, but is it any good? Does it do what it says it does? How accurate is it? I kinda find it hard to believe that you can just pull a little and knob and then you will be in drop d. Is there anything i need to know about installing it? Can it go onto my Jackson Kelly KE3?

It does basically accomplish that. However, with my FR, when I tune my guitar, I make sure string 6 is nearly as far down as it can go (with a little bit of room to sharp the note) so that when I want to go to drop tuning, all I do is loosen the peg to pitch.
I play guitar in a ska band.
Modded MIM Strat > Fender Tuner > Bugera V55HD > Custom built 2x12