Problem making a DVD with subtitle in Mac

[pmurad]

After a lot of tests, I still can't get what is going on. Let's begin with the history of my problems.
When I bought my MacOS I saw that was much more hard to "create" a dvd like it was on windows.
My problem was: I wanted to put subtitle in my movies and I could have no success.
Now this problem is partially solved, I'm using iFFmpeg for some movies and iSubtitle and Submerge (until now my favorite) for others, but why 3 different Apps?
iFFmpeg when you hard code the subtitle it generates from the .srt another subtitle .ass and it's need to be edited using jumbler (other app).
When I use subtitle, in my opinion could be the favorite but has just one problem, there is a black label behind the subtitle that could not be edited and moved.
Submerge do all I want.

Ok, let's talk about problems.

I'm not a specialist to work with videos and all my DVDs are Dual Layer, I saw when I create a .vob from the original file, the file is small. It's efficient, but small, even when I set the settings in HIGH, and it's fast.
iSubtitle and Submerge does not create .vob, so first I need to convert to .mp4 using H.264 as a codec and I put all in Maximum and it take hours so after I use toast with the file hard coded and it converts to sm stuff and so burn.

The process seems to be the same in burning. The question is, why when I create a .iso and so burn it takes just 1 gb from a DVD DL from 8 gb, and when i burn the other 2 with toast takes almost 5 gb for each movie.
I'm losting or wasting something?
I mean, even putting the .mp4 container in the maximum the toast will convert to fit a dvd...

Here are examples of the same movie made with 2 of the apps.

iFFmpeg

General
Complete name : /Volumes/video/VIDEO_TS/VTS_01_1.VOB
Format : MPEG-PS
File size : 1 024 MiB
Duration : 55mn 34s
Overall bit rate mode : Variable
Overall bit rate : 2 576 Kbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Default
Duration : 55mn 34s
Bit rate mode : Variable
Maximum bit rate : 9 000 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy

Submerge

Video
ID : 2
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L5.0
Format settings, CABAC : No
Format settings, ReFrames : 2 frames
Format settings, GOP : M=2, N=24
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1h 25mn
Bit rate mode : Variable
Bit rate : 7 642 Kbps
Maximum bit rate : 21.0 Mbps
Width : 703 pixels
Original width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Original display aspect ratio : 5:4
Frame rate mode : Constant
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.755
Stream size : 4.54 GiB (98%)
Language : English
Encoded date : UTC 2012-10-31 01:51:19
Tagged date : UTC 2012-10-31 01:58:26
Color primaries : BT.601 NTSC
Transfer characteristics : BT.709
Matrix coefficients : BT.601

What am I doing wrong? Pls

[Baldrick]

I'm moving you to our mac section. ANd please use a better thread title that actually says somehting about your problem. I edited for you.