So one thing to point out is that when you raise the whole track 6dB (as in Hog Time's example) you are also rasing the noise floor by that amount. That is something to listen for.
Whether you normalize everything is up to you, although once you do it means starting the mixing process all over again, because one track may have been increased 18dB and another only 2.
The time to get the good levels is during the recording process so the signal-to-noise ratio is good and the convertors are getting a good strong signal to work with.

For what it's worth I don't normalize every track. I rarely normalize any tracks, but will use the gain change plugin if a track needs it. A lot of realdrum tracks seem to need a little boost I've noticed.

I do not work here, but the benefits are still awesome
Make your sound your own!