I have a Rode NTK for a couple of years in my home studio. I use Grace 101 as a preamp, apply some mild compression with RNC, and go directly into my RME Multiface analog-In.
I more or less like NTK. It is a bit dark, warm, and it seem to lack some.. how to say... high harmonics if you will, or crispness. At the same time it has 'body', it sounds full. And I would prefer it in a voice-and-guitar acoustic type of arrangement.
I recently tried a $200 StudioProjects C3 and surprisedly liked it for its crisp sounding in a rock ballad. It cuts through a dence mix much better than NTK. But it lacks 'body' so it sounds king of thin in an airy acoustic mix.
NTK also has some fairly noticeable humming noise, I guess from the valve inside.
I was looking at Neumann mics up to $2000 range (TLM105, U87Ai) as my next step towards quality recording. Any advice on that? Stupid question, huh? :-)
Nick