Firstly the main reason you see the reference to Top loading is it implies its an Eddie Lee case, though usually this statement starts with EL Top loading..
EL cases are more sought after due to them being more gen like than the cartel/DSN etc versions . As I am aware EL produced 5 versions of the case all with different errors. However the cartel did at one time sell top loading cases.
Regardless of the differences in ELs cases and the old cartel case the top loader removal point can be clearly seen and adds to its genlikeness.
The biggest issue with a top loader is the potential for exploding crystals due to incorrect fitting, DIY removal which can be affected by changes in temperature, excessive pressure on single points of the crystal as it sits in the bezel. I guess this is why the cartel changed to fixed bezels.
Eitherway the movements can be removed back and front in nearly all cases.
So an EL case, all of which are top loading, is the best rep case available although with varying errors. Not because so much that its top loading but it is a better case as well with the top loading removal point being seen.
The standard rep cases including DSNs have the wrong shape and incorrect bezel not just the top loading bit but angle and thickness.
Hope that makes sense