Just installed a GFS Xtrem/Roller Bridge on my STL-Ash. Generally, it works very well. The guitar stays in tune and it's easier to string then the Bigsby that's on my other guitar. The roller bridge adds quite a bit of height, so shimming the neck is necessary and the bridge pickup is raised as much as it will go. GFS does not send instructions or templates of any kind, which meant that I had to spend quite a bit of time lining things up and making sure the bridge was in the right place for intonation purposes. In end, I did get a good set up. I'm looking forward to putting it through it's paces at a couple of jam sessions this week.