Tom: Yes I compare file sizes .
I know it was the same in PTE8 and 9 but I often use this possibility.
With PTE it is easy to adjust the mix between for example comment's track and music track. But if you want to adjust the loudness of the mix, it's not easy as you cannot adjust the overall loudness of the slideshow. So I export the audio, put it as a new track ans adjust the loudness and mute the comment and music tracks. To get an optimized exe, I must ask PTE to convert tracks to MP3 for exe.