So whats improved in 4 over 3?

Nevermind, just did some quick dicking around and the changes are obvious, this is superior.
Moving pieces is no longer snap to grid, you can rotate while using the move tool, making the regular rotate tool completely redundant. The 3D view is better, high lighting the selected piece with pale red instead of a red outline. Impressed with it so far, but only just got into it.

One thing thats annoying. I cant get .pdo's unfolded in Designer 4 to open in Viewer, at least my version of Viewer.

>>538317
"Pepakura Viewer, a dedicated Pepakura Designer file viewer, is included."

>>538358
Yeah the Viewer that comes with ver4 of Designer opens it. But old Viewer/Designers cant.

>>538363
I confess, I cheat because I have them both in portable and I work well, even though I already have version 4.0.0 and is installed ...

>>538366
You can install both version in same PC/Laptop. That is no problem.
No.538363 mean If you unfold model from Verion 4, you cant use Viewer 3.X to open.
I tested it, it has this problem.