CEH  I have been using MovieGate for 4 -- 5 weeks now, and I strongly recommend it. It is an excellent tool for authoring DVDs with menus -- it usually takes me 2 -- 3 minutes to select the video files, edit the menu and start it encoding. I run OS 10.5.6 on a quad-core system.

Typically, I want to encode and burn .avi source files. MovieGate runs a process for each video file, so that if I'm burning a DVD with 4 videos on it, MovieGate runs 4 processes, taking full advantage of the quad core processor. It is very fast and the quality is excellent. The developer is amazingly responsive, and if I have had any problem he usually comes back with a new beta within a few days.   
(Version 3.04)