Frustration

[aroy]

Learn to use and manage high ISO. If you're shooting at ISO 200 in a dark hall you're doomed before you start. With the D7100 you can easily shoot at ISO 1600 and barely notice it. Yes, there will be noise, but Camera RAW does a good job with Noise Reduction, and Nik Dfine 2.0 does a better job if you have it. A noiseless picture that's not sharp is useless. A little noise bothers the photographer more than anyone else - but unless you're going into the Hi range you should be able to manage it.

I agree with this. What noise is there at ISO 1600+ will be confined to the darker areas, the bright portions will be practically noise free. Noise reduction softens up the images, so a sharp image will go a long way in creating a relatively noise free final result.