I got it up and running yesterday. It looks quite nice with my Intel Mini:
http://www.wiredbynature.org/comp/mac/mini/pics/ministack.jpg
The color is close but is actually a bit darker than the Mini's silver. The blue light on the front is a nice touch; it's not blindingly bright like most blue LEDs. I installed a 500-gig Seagate drive in my MiniStack v2. Installation was a snap: screw the hard drive into the mounting plate and set it to Master, plug in the power and data cables, screw the mounting plate back into the enclosure, and press-fit the lid (it has clips) onto the top of it. There aren't any special clips or indentations for the Mini to slip into; it's purely a friction thing - just drop the Mini on top and line it up with the sides of the enclosure. I am very pleased with the overall looks; it fits in quite nicely with the Mini's decor.
Regarding noise, there are two types of noise: hard drive noise and fan noise. My hard drive is fairly quiet but is definately audible. The smaller Seagates that I own (250-gig for example) are nearly dead-silent; the 500-gig drive has more noise than those do. The fan kicks in after awhile. It is noisy in the sense that you can hear it, but it is not an annoying noise in my opinion. It sounds like a very distant vacuum cleaner, like you would hear from a different room. More soothing than annoying, I would say. Definately a nicer whir than, say, a Dell desktop. If you happen to be working in a completely quiet environment, it will be
very noticeable. The nice thing about having a fan is that it drowns out the hard drive noise, so there are pros and cons to having a fan in your enclosure.
The hub does NOT function if the unit is turned off. I personally find this very annoying. I only like to keep my external hard drive on when I am making a backup; this way it stays safe and protected and gets less mileage (= longer life). The workaround here is to turn the unit on and when the hard drive appears on the desktop, drag it to the trash. You can then re-mount it via Disk Utility when you want to use it again, without having to turn the entire unit off and on again. If the fan is running, it turns off a minute or two after you eject the disk. Small hassle but what can you do.
Overall, I feel that it was a good purchase. It gave me extra USB and Firewire ports, as well as an external hard drive, without ruining the aesthetics of the Mini on my desktop. Now I just need to write an AppleScript or something to re-mount the drive without having to open up Disk Utility and remount it myself...