I have had the Edge and the 300S, so I can't speak for the 300L. Contrary to what some think, I believe the Edge is a better performer overall. It has very little pitching tendency, and point rolls better than the 300S. Both have the same fuselage and tail group, with the differences in the main wings and the cowl. The Edge also holds a line horizontal well, with the 300S holding a better vertical line. This presumes you have both properly trimmed and set up.

It's all just my opinion, and I'm certain that by this time tomorrow, you will have more opinions than you know what to do with

Best of luck in your choosing. You can't really go wrong with any one of the three.