I just install one on my Start (50's reissue, Mexican)
Received this morning, I put roughly 25 minutes to install.
Installation is easy, the instructions are clear, but the video on the site of the Hipshot is even (here http://store.hipshotproducts.com/cart.php?m=product_detail&p=115 )

My vibrato is a Vintage, a stroke is reduced compared to other models.
It is not necessary to pierce the body of the guitar to go freelance, just shorten this one.
Thus, changes in the body of the instrument are minimal since there are only two screws to fix to add the beast.

So given level of agreement is nickel.
Finally, nickel is not exactly the word.
Take for example the low E string. Granted perfectly, one goes down the vibrato arm until it abuts against the pickguard and then releasing it not fall entirely on the note "perfect", fit the rod and release to make everything up .
But it is surely a problem of adjustment, since doing the same test in reverse (by pulling the vibrato arm so) the original position is well taken.

I recommend it to all those who want to stabilize their vibrato, without breaking the bank too (36 euros spring, it is certainly a bit pricey, but it's still available!)
Feel free to contact me if you want info.