Wow!! The 1.4 player is even better than 1.3. They have made changes so that the window doesn't resize every time there is an aspect ratio change in the window.
This player is built from the same technology used to make Apple's DVD Player, so for playing standard DVD movies, there is little difference between InterActual Player and Apple DVD Player.
But for the new range of DVDs enhanced with DVD-ROM features this player really enhances the movie watching experience.

There are a lot of existing titles with ROM content, that will probably never work on the Mac, unless Apple somehow ported ActiveX to the MacOS.
This is a bummer, but enterprising users will find that a lot of content on DVDs such as Shrek, Spirit, Sinbad, Pirates of the Carribean etc. is just HTML, Flash and Shockwave and can be run in your standard web browser. You just need to look in the "common" folder on the DVD, which is where the DVD-ROM content is stored.

This product is only a few months old, and already we've seen half a dozen DVD releases that support it. I think if all us Mac users throw our support behind DVDs featuring Mac content, then the movie studios will start releasing more and more titles.