What are the differences between a nb and a cs? How much diff in brightness, tightness, mids are there? Am I right to say a CS is better for rhythm work and the nb is more vocal for lead work?
There are similarities, as they're not a world apart considering the wind. The way I understand it, the Nailbomb is like an overwound Cold Sweat, but with an Alnico 5 magnet. CS has a ceramic magnet; it's brighter, has a faster tracking and tighter bottom and less mids. They both have quite a full bottom.
I have experience on them both. In my opinion, the CS is best in a warm and full sounding guitar, giving a tight and aggressive (but organic) tone there. I have it in a guitar like that and love it for leads too. I usually just match a guitar with the right pickup and use different amp settings / an overdrive pedal for leads. I don't really think of guitars like 'this is for leads' and 'this is for rhythm', although they sometimes do lend themselves naturally to certain things.
-Zaned