My Book Studio observations.

• It's made of plastic. Ick. Cheaper HDD cases are made of aluminium.
• I wanted to put it horizontally at first, then I noticed the vents are only on the top and bottom, so it would have less ventilation when lying horizontally. I don't think it's designed to be put horizontally, so try not to.
• It's got no fans, so it's quiet, but hotter.
• I never thought of HDDs as hot, but you can feel heat rising out of the vents if you put your hand over them. Not sure if this is bad for the HDD.
• Doesn't look easy to open. No visible screws.
• I like the LED lights. Rather than just 1 or 2, there's a whole row of them. When in use, they light up in a running pattern. When falling asleep, they alternate. Makes a good night light, but may wear down your HDD. I didn't install the software to use the capacity gauge.
• There are 2 Firewire 800 ports. Can I connect 2 computers at once?

So far I haven't used it for anything other than Time Machine.