Great hardscape! Looks good, only thing that kind of bothers me personally is the slope of the substrate. Since it slopes in the direction the rock points, it naturally leads the eye right up and out of the tank! Well for me it does at least.
Also, an upgrade to the lighting would be great as well. Maybe 2-4 t5ho? Great start!
You have a stone with some great character. I too like your slope but I feel the flow of your stones is interrupted by the gap. Have you tried merging the big stone and the smaller one on bottom right into one? If it's possible it might change the scape from a stone to a mountain.