Not much to add, just my personal journey with the technique.
I first woke up to this amazing option with the Everly Brothers' 'I'm On My Way Back Home Again' (a late-'60s single). That was Clarence, of course. I wanted one immediately but had to wait.
An English luthier named Cedric Thorose offered to replicate the Parsons/White bender on my '82 JV-Series Tele and did a pretty good job. Sadly, because it was a great guitar to start with, it was stolen a few years later.
I tried a Bigsby palm-pedal but couldn't get accustomed to the hand position required. Hip-Shot? Felt unnatural, too.
Then I got Joe Glaser to adapt my G&L Asat Classic. It worked like a charm. I had another JV fitted with Joe's bender (that's in Germany now - Candy Apple Red) then, finally, my current favourite electric, a Custom Shop Thin-Skin '62 reissue got Joe's bender. I love the unobtrusive look of it all and it certainly works perfectly. Locating the ball-end can be a challenge but that's the only 'con'.
At some point, I spoke with Albert Lee about it. I'd played his 'butcher's block' Tele (with the Strat neck) with Dave Evans' Pull-string and had admired the smooth action of the mechanices. He said that he 'couldn't get on with' Joe's bender because it anchors at the neck-plate and not the traditional shoulder-strap fitting.
I was working and earning, so I splashed out on a used Thin-Skin in Butterscotch and had Dave fit his unit. Pretty expensive indulgence, all in all.
The verdict?
Joe's is mechanically superior and, because of the rolling bridge-piece (like a steel's changer), there's no wear on the string.
The Evans has that see-through back with all the 'works' on display and it's heavier than the Glaser. It retains the old brass saddles and the strings saw back-and-forth and cut a groove in the metal.
Having said that, Dave's unit wins on sustain! The pulled note sings out from the chord you're playing and has an inspiring tone.
Of the two I now own, the '62 thin-skin in Lake Placid Blue is my preferred guitar (I like rosewood fingerboards), but the Evans unit has the edge for its remarkable sustain. I haven't yet broken a string on it but it won't surprise me if I do.
Pic 1: Joe's bender on the red JV.
Pic 2: Me playing my first bender (Cedric's) with the Big E.

Pic 3: The Evans mechanism on display.
Pic 4: The Evans non-moving bridge
Pic 5: The G&L Asat Classic.
Pic 6: This shows Joe Glaser's moving bridge-piece.





