Shooting with theese cameras you some times have noisy/grainy video clips - mostly shooting with low light - but also at daylight a hazy sky tends to get irritating noisy.
This is however easily filtered with the Neat video filter:
which often surprises in making nearly unusable clips 1A rated.
As this filter is heavy on the CPUs it is a good idea to render the clips in question to AVI files and then use this output for editing.
BTW this type of cameras gives the possibility to mix quality stills into the project. You sometimes get a good effect mixing in 3-5 stills taken with few seconds intervals - and maybe fitted to the beat of your background music... :-)
Alternatively you can probably use some of the software you already have.
I have a primitive film maker program - name escapes me at the moment that came with the camera software (on the other pc that is out of order at the moment) - which I load the Canon video sequence into. Then I render it to uncompressed avi and Vegas is good to go.
On this pc I use Camtasia to make the uncompressed avi file.