Not to get into a tiff but I have used the C1 on about 20 tunes and though the vocals are OK, none of them stand out particularly across a variety of different preamps.
The V67G, if you use with a warm preamp, can get mushy, I agree. But the vocals, primarily ballads, just seem to stand out better in the mix than the C1 does. The mix by the way is usually piano, acoustic guitar, bass on the material I am refering to. Drums too in most cases.
The only disclaimer is my experience was on male vocals, baritone.
I don't think you can make any general statements about any mic and the C1 is a good mic. I used it for a lot of backing vocals before I picked up an NTK. I needed to sell one mic to get the NTK and found the C1 was pretty much a one trick pony that I was using less and less.