I've followed the adjustable bridge vs solid bridge arguments over the last few years. The main argument for the solid bridge is that the vibrations of the strings only go through the 2 metal screws to the underside of the bridge, and that that inhibits it at the outset.The solid would then be a better choice. So, many people have tried solid bridges with various results. I'm not going into the pros and cons here. That has been done extensively elsewhere. But there is one thing you can do to make the sound travel more to the bridge base on an adjustable. You can easily stick some wood between the upper and lower section, and even some between the lower section and the top of the mandolin.Then you can hear if there's a difference, and take it out if you don't like it. That way you can compare and don't need to spend money and effort into a solid bridge. Unless you're big into maple bridges instead of ebony, of course.