I got the Scootworks one. They're all pretty much the same, just a longer trailing link.
I went 2" and had problems bottoming out when riding 2 up. I think some work on the splash guard would have helped, but I didn't want to make holes in it for fear that water would go where water shouldn't go.
I ended up with a 1" drop, which doesn't sound like much, but it's a noticeable difference and I like it.
BTW, with the Scootworks kit, it went right in with no adjustments or modifications.
My biggest fear is when I die, my wife will sell all my guitars for what I told her I paid for them.