Ah, differing opinions I suppose, lol. I like the channel look. Another consideration is having maximum real estate for coral. It's hard to imagine when starting out, but space can get gobbled up quickly as your wallet empties into the tills of the coral mongers.
On my next build, I am considering sawing the bottom of the rock flat. It will provide the ultimate stability and looks like a reef head in nature instead of a boulder on the sea floor. Many are reluctant to cut up these expemsive rocks but the technique is used to make terrestrial rock gardens & stacked stone fences look natural, mature & permanent.
The old "stack of rocks" look is kind of what I did in the begining with a few twists like varying peaks & caves. This is probably the most unimaginative style and usually provides the least horizontal space for coral mounting.
But after a few years of lush coral growth, the underlying rock contours become obscured and much less obvious as the eye focuses on the corals, fish and other aquatic life.