As a matter of fact...
Just yesterday I did a test on several different mics at the store (as I am looking to upgrade). The 2 I chose were the Neumann TLM103 and the Shure KSM44. However, not being independently wealthy, I have to try and choose between the two. So...
I recorded a couple of blips of me singing at the store on the same type of DAW that I have at home. I then went home and sang the same "blip" into all of my mics to compare. Anyway...I own all three of the mics you mentioned (plus some).
Here's the scoop (at least the way I saw it)...
For recording, of the bunch, the C1 is FAR better than the other two. The AKG and the Shure, however, are much better live. Which one totally depends on your system. I used to use the C535's exclusively, until I upgrade my sound system. It then sounded way too "tubby". The Shure soundes cleaner and the vocals seem to sit better in the mix. (If you are indeed interested in a live vocal mic, I would also suggest
the Sennheiser E865. Sonically, it sits somewhere in between the AKG and the Shure. It has more body than the Shure, but not a muddy as the AKG. It sounds FABULOUS!)
The C1 is a pretty good sounding mic, even up against the "big boys" (well, at least the "medium boys"). I actually prefer it, in some ways, to my NT1000 and it even sounds good next to the KSM44 and the TLM103 (though these two sound bigger and more open).
If you're interested, I could post some mp3's of my test, so you can hear it yourself...