I can say with confidence that to get a nice and sharp image out of MLV you need to do this: (it works for me)
WHILE SHOOTING:
1st. f or T stop MUST be above 4. (anything below, you need to have a REALLY good lens and REMEBER: REALLY GOOD does not measn costing in the thousands!

)
2nd you MUST have the main light source BEHIND your camera
3rd Lens hood or matte box will prevent flares and help sharpen the image a bit by keeping your front element in "the darkness"

4th Stay as still as you can / need to be.
5th MAKE SURE lenses and sensor are clean.
6th Make sure what you actually want sharp as a razor is focused correctly
7th Record the image with a flat profile, in the canon menu picture style (sharpness 0, image contrast -4, image tone -2)
WHILE POST-PROCESSING:
The clarity parameter in lightroom does miracles

Look for sharpen image, unsharp mask or stuff like that but BEWARE ofartifacts! (I personally don't use them very often, The clarity paramete in Lightroom does the job well for me)
And that's it pretty much! If you still get not really sharp images, i think is either one of this three options:
1) you are using very low quality lenses
2) you are not setting up your exposure settings properly
3) there is something wrong with the MLV files o_O??