In VEGAS Pro 16.0 I'm given (at least) three options if I want to render a 1080p 30fps video for YouTube upload:
Sony AVC/MVC, template "Internet 1920x1080-30p"
Use this setting to create the highest quality 16:9 file suitable for uploading to Internet sites. Audio: 128 Kbps, 48,000 Hz, 16 Bit, Stereo, AAC Video: 29.970 fps, 1920x1080 Progressive, YUV, 16 Mbps Pixel Aspect Ratio: 1.000
MAGIX AVC/AAC, template "Internet HD 1080p 29.97fps"
Use this setting to create an MP4 (AVC/AAC) file for progressive internet downloads. Audio: 192 Kbps, 48,000 Hz, 16 Bit, Stereo, AAC Video: 29.970 fps, 1920x1080 Progressive, YUV, 12 Mbps Pixel Aspect Ratio: 1.000
MainConcept MPEG-2, template :HDV 1080-25p (Note 4:3 aspect ratio)
Audio: 384 Kbps, 48,000 Hz, 16 Bit, Stereo, MPEG Video: 25 fps, 1440x1080 Progressive, YUV, 25 Mbps Pixel Aspect Ratio: 1.333
These are just templates and it seems each can be customized (for example, MainConcept template can be customized to be 30fps and 1920x1080). So is there any big difference between each format? I noticed MAGIX can support VBR to reduce filesize.