Rick,I guess the bottom line is, if you are happy with the stock clouds why change, on the other hand as the FSW clouds and 'randomiser' are free it won't hurt to take a look.
If you do decide to try back up the default cloud bmps first then you can always go back.
I have only just installed them so haven't played with them much but they don't seem to impact on frame rates, so that's a good thing 
'Vulcan'
8nm NE of EGCC