Andrew,
I had some of the GIK traps, but ended up replacing them with Realtraps (
www.realtraps.com), largely because I wasn't happy with the aesthetics of the GIK traps. (I also found the Realtraps easier to hang) You could probably slap a few mondotraps up in the corners and use the space behind them as a broom closet or hamper or something!
Some of the auralex things look nice (like the Sonosuede stuff), but they won't give you enough low frequency absorption, unless you get into the big ugly LENRDS or MegaLENRDS. The Realtraps will definitely help with all of the issues you list. I know they did for my room.
I've been really happy with the Realtraps (and my wife is happier with them too!), both in what they do for the sound of my room and the aesthetics. But I should also mention that their support is superb. Both Ethan and Scott over there are really helpful. I dealt mainly with Scott, and he spent a lot of time with me, asking a lot of questions, to come up with the best plan for my room, and he even came up with some great ideas to make some of my treatment less noticeable in the room, which was important to my wife. Actually, come to think of it, Scott lives in New York. Brooklyn, I think. So I imagine he'd have some good ideas for treating small apartments.