I have one of the hinged benders (its packed away right now so I can’t confirm the model).  It works fine for Yarmouth ladders etc.  But the hinged piece is both a liability and a help.  When clamping the ladder stiles into the tool, one has to navigate the hinged piece flopping about.  Also, the part can slip into the gap at the hinge, and if you twitch when it is partly caught in there, you can get an unwelcome fold line.  I avoid that successfully almost all the time, but need to be careful.

Before picking up the hinged version I used a straight edge version.  I didn’t like the risk associated with slipping a razor blade under the etch in order to fold it.  It was hard to insert a razor blade evenly, from end to end of the etch.  Instead, I found the blade tended to go under one portion of the etch, raise it slightly and that allowed the blade to go under the rest of the etch.  But this gradual insertion of the blade could distort the etch.  For example, the etched ladders can tend to torque at the etched holes for the ladder stiles, their weakest point.  

The hinged version removes that risk.  Generally I think it is a superior tool for folding along long skinny parts.

Rob