When I was about seven, we started going to a new church. If we had sung "Hallelujah! What a Savior" before then, I honestly don't remember it. This was the pastor's favorite song, so we got to know if very well. I used to play it all exuberant and loud. But when I got to reading the words...reflective is also a good style for it.
One of my favorite things about this arrangement is that it is arranged using simple timing (no eighth notes).