Personally, I quite like the look of the SMS C/F decals, I use it whenever is appropriate with very satisfying results.
SMS aren't the only manufacturer of the C/F decal though, Renaissance make it too with a darker grey to it, as do a few otheres.
I think the spray through mesh method doesn't look at all realistic though.
Here is a photo of where I am using the C/F decal on my Safari Impreza, which is not far from finished:
You can see I used it on the snorkel pipe and you can also see some on the interior door panel, I think it adds to the realism of the model.
Ray