I rarely see the app make a difference on conversion time.
All that aside, did you try VLC Player to convert? It's free, nod to Ninite.com for getting it and with many tutorials on conversion, should be well documented.
Supposedly a free video converter. It may be free, I didn't get that far after I saw irt was taking in excess of 16 HOURS to convert a 3.3MB MP4 file to an AVI format. It may actually work but I'm not willing to dedicate 16 hours or more to 1 D__N application