[Why an IOC costume?]

I don't know if I'm "allowed" to reply since I haven't got my costume yet (It's on its way home, though), but here's my view:

1. As it's been said above, imp. officers totally get it. I mean, look at those fancy suits with the colorful rankbars and belts. There's no better finished uniform in the whole galaxy. 
2. The suits, besides elegant, are comfy. Poor stormtroopers can't even sit to enjoy the space view. 
3. Officers don't get as much atention as troopers, but they sure give variety and complete the squads when marching. (They look totally awesome next to Vader).
4. Currently, I do not have much spare time to work on a complex armor, so begining the "collection" with an officer costume it's been perfect for me (I'm now waiting for my ISB officer costume and items to arrive).  
5. You can even reuse some parts to make more officer's costumes.
6. Also, they are cheapear than most costumes so they stand as a great way of entering at this hobby. 

Thanks for asking and sharing your experiences, it's a pleasure to read all of you!