I have always preferred using Toast to burn DVDs over the free iDVD included with all Macs as part of iLife.
Most of the DVDs I burn are of EyeTV Freeview (MPEG2) recordings so was always SO much quicker than iDVD ever could be.
Also for some reason iDVD never really liked the fact I was using PAL over NTSC, not sure why.
Of course you sacrificed functionality and other stuff in the menus, but my view was, was I going to watch the menus or the film?
I use to use the video conversion functions (which were useful) however I have now switched over to VisualHub for that.
I do use the compression facility when compressing large DVDs.
Sometimes an EyeTV recording won’t fit on a standard DVD, and DL-DVDs have not been a favourite of mine, either I created coasters or they weren’t available as printable DVDs.
So I use Toast to create a DVD Disk Image using the recording and then use the compression (use to be Popcorn) to reduce the disk image in size so it fits on a standard DVD-R.
Overall Roxio Toast 9 Titanium is one of my favourite applications for the Mac.