diff in qual between 2.2 & 4.3 GB DVDs

[icebergx]

Hello everyone,
another question...
If I have a 700 mb .avi movie and want to burn it to DVD will it make much difference (in terms of picture quality) if I choose to convert the file (using TMPEGEnc Plus 2.5) to 2.2 GB rather than 4.3 GB. This would enable me to put 2 DVD movies on to one DVD.
Obviously this may mean reducing the relative bitrate by appx. 50% (compared to a full 4.3 GB DVD convertion) but I asume that this bit rate should be succiciently high to maintain most/all of the original .avi's picture quality. After all, I will be nearly quadrupling the size of the original movie.
Also, can there be any compatability issues if I choose just to burn only 1 2.2Gb movie burning images which only take up 50% of a DVD+R (thererfore leaving 50%of the DVD unused.

Thanks,

Iceberg.

[Baldrick]

One topic is enough
http://www.dvdrhelp.com/forum/viewtopic.php?t=211374&highlight=