Well, the C-1, although by all accounts, a fair vocal mic that is quite usable on guitar, is cardioid only, and I wouldn't call it transparent either. It's a mic that will give you one good sound. If you like that sound, consider C-3, a mic I use often. It is tailored as a vocal mic also, but is multi-pattern. We're not talking about the best vocal mic or the best guitar mic, but a best first condenser mic. I think you start with one that is transparent, versatile, and inexpensive. A mic like B-3 will give you a good learning tool that will still spend some time up even after you own much more expensive mics.
I think C-3 is also a good choice, but comes with a little flattering color that only flatters some things, like C-1. You see, the B series flatters nothing, just the facts, ma'am. I think that's the right place to start. Then you slowly add mics designed to flatter exactly what you got.-Richie