Tank is looking pretty good as is. I have to agree with what is posted above, you did a good job using a tank that has a less than ideal footprint.
To try to add to the tank and keep it progressing, I would:
1. Get a couple more small fish. A couple fairy or flasher wrasses, couple anthias, or a goby.
2. Get more corals!!! You don't want to overdue it by overfilling with frags like some people do. I like the openness with space to grow in, but you have plenty of space for some more corals right now.
3. You may need more light. Not sure the wattage and output of that HO, but you may have growth and color problems with some of your SPS with it.
Keep up the good work!