Honestly if I was to do it again I would just get a regular tank and do lighting etc. the way I wanted to (would probably be cheaper in the long run--unless buying used) However, many people like BC's and they do look sleek. I like my biocube, but it just wasn't flexible enough for me when I wanted to upgrade my equipment. If I wasn't such a gadget geek it would probably be fine though
To consider:
1. tend to get hot--
may need a chiller or fan
2. replace stock pump with an MJ900 or 1200 if you want to decrease some heat and increase a bit of flow (stock runs fairly warm-I never did this though)
3. switch fans for lights so they come on when actinics come on
4. make sure one fan is blowing in and one out (manufacturer screws up sometimes)
5. difficult to hook up a sump or other equipment without modifying or doing away with the hood entirely
6. will definitely need more flow. Seio820, koralia 1 or 2 would probably work
7. heater recommended for night/shifts in temp.
8. toss the bioballs, can use chamber 2 for a fuge, for lr, for media....and the filter is not "needed" per se, but if you want to use floss just replace on reg. basis
9. may want to widen space from chamber 1 to 2
10. 2 skimmer options I know of if you want them to fit inside with the hood; sapphire nano skimmer, BC skimmer. I have heard the BC skimmer is not terribly great, the sapphire is pricey
11. Stock lighting is fine for softies, you may want halides if you do other corals, but that all depends. I have seen some very nice mixed BCs, even with anemones. Halide will of course increase your heat. Also if you go to nanotuners.com there are diy lighting options that add more light/better fans etc.
All these are options you can think about. People run them stock as well.