I've had discussions with some of the others who've said that the Makita is good because it's more affordable and, evidently, easier to use and less prone to damaging your rail compared to the original FSV.
I've only used the FSV/2 and have found them to be quite simple and easy to use. The connector that goes into the inner/under slot is, evidently, the new design that expands in the track when you screw in the allen screw. That seems to work very well and eliminates the issue of deforming the rail. However, you do have to be careful when taking them out because I've twisted the allen key one twist too much and the screw falls out. And if you're not paying attention and lose it, you'll have the irritation of having to get another.
That said, the upper rail (I believe) is still the old design with the allen screws that goes through the connector and presses up againt the rail. My understanding is this causes the deformity when you screw/tighten the screw too much, so you have to be conscious of that and not over torque.
After all that, I've found them to be easy to use. I followed the Sedge tutorial where he says to keep a slight gap between the two rails and with the new connector that pushes outward, it seems to 'auto-align' the rails.
