Can't comment on the rest of the apps mentioned, as I've never tried them, and am a tad old school where it comes to manipulating video / audio.
But am a long time user of avidemux, and the good thing about using that (not saying it doesn't apply to the other conversion tools, as I don't know, but it definitely applies to avidemux) is that it will just convert and remux the audio, it won't (unless you tell it to) convert / re-encode the video. That may well save quite a lot of time, if other tools do re-encode the video.
You can also batch things up, at least in certain versions - I had a discussion, elsewhere, regarding the playbook, video, and using avidemux to bulk convert a lot of video (well the audio really) for playbook use - and it seems the batch functionality may have disappeared in the latest releases. But the verson I use (2.5.3) definitely allows you to do batches of conversions, and I'm pretty sure is still available at least from the section on videohelp for avidemux.