I bought this with a Vibramate Mount kit (Which, unfortunately, didn't fit.) By this point I'm feeling pretty stoked because of the weather, E3 and my parts arriving. I thought: "Meh, I'm sure I can fit this without it."
Thankfully, the B5 came with very clear, specific instructions. I did come across a small problem though, in that my guitar only had the one bridge. So I couldn't remove the existing to fit the Tremolo. I didn't have a reference point.
I grabbed a pencil, drew two parallels from the bridge and lay the Bigsby in the middle and thread the string included like this: E, through Bigsby, up to high E
After I had lined it up it was just a case of marking out the holes I needed to make and drilling it in
So there you go, an 18 year old with little to no experience fitting anything onto a guitar could mount a Bigsby without ruining the sustain or action of the guitar. It's really no big deal fitting the kit, I would do it again without Vibramate mount kit to save on the £50 something that a Mount kit costs.
As for the looks, it is a beautiful piece of kit, I was worried that it would look intrusive but I needed something to take up the space on the body of the guitar. The arm looks exactly like the rolling tremolo and style of a traditional 40's Whammy Bar. (Most Likely because Bigsby has been around since the 40's.)
The arm folds away nicely and still fits in the case just fine.
Stringing the Bigsby is a real pain though, There is a solution for it, if it bugs you enough to spend the money on it. I fit a Vibramate String Spoiler to the instrument which has done nothing, looks wise, but makes stringing so easy.
The piece is totally worth it's money, sounds great, handles great, and was a laugh to fit. I haven't noticed a change in the Sustain or Action, but as expected I do have to tune it more often. I would advise on getting some decent Machine Heads.(If you haven't already.