I'm really impressed.. This is the second one of these I have purchased. The last one went on a PRS SE and sorted out a few stability issues very well. The latest one I put on a Jem 555 I modded with a proper Floyd and EVH d-Tuna, it works perfectly holding the tuning on the other strings when drop tuned. I was also going to tune the Jem to E flat and drop C# with the d-tuna, but my string were a bit heavy, dropping tuning down to D and Drop C was as easy as on fixed bridge guitar, no messing about having to re-tune the strings and adjust the tension on the trem springs :D
Pro's..
Cheap
Works
Easier than blocking
Easy to fit / remove
Cons.
Probably wont hold tuning with a broken string unless you wind the pre-load right up
No more trem flutter when sliding my hand of the wammy bar :(
Tricks for setup.
Wind on about 1/4 preload. It make it easy to fit and needs to be set around there for double bends and drop tune.
After its set up and holding the block - over tighten the trem springs a little.
Worth a try if you are looking at a trem setter, only takes 2 minutes to remove if you don't like it and will only leave 2 small screw holes.