Personally, I am a big fan of the super slim. Smaller = better. Yes, the sliding tray cover seems cheap. But everything else is just fine. If both are at the same price, I will get the superslim over the slim, esp with if it comes with more free games or psn trials.
How is the "heat" factor on the super-slim?
I had the very first gen of the slim (120GB), and it always got sort of hot. 3 years later and I would say the back of the console gets very hot, and the fan goes pretty loudly too (especially after about an hour or more it starts to really crank up).
Would love the super-slim if after 2 hour gaming session it is still reltaively cool. A little bit of noise out of the disc drive wouldn't bother me (i remember the PS2 slim made a bit of noise while it was reading discs). In my experience that only happened during heavy "loading" though. If it's just a steady streaming of data it was much more tolerable. So hopefully the PS3 super-slim is the same way. But to me, the "heat factor" overrides everything.