I'll try to tell you everything I know about UC-Logic tablets.
In general: The stylus uses 1 AAA battery, unlike Wacom tablets that require no battery. Apparently, this type of tablet is cheaper to produce, but you can read the technical details on Wikipedia. The stylus automatically sleeps, so the battery lasts pretty much forever. Holding the stylus above the surface (hovering) moves the mouse. Tapping the surface clicks. The harder you press, the wider (or darker) your brush strokes are in a painting program. It's pretty intuitive. The nib is a plastic nib that will wear out, especially if you use it much or use it on a rougher surface (e.g. tracing on paper). Finding a replacement stylus will be challenging, a problem exacerbated by cheap production quality.
On Windows, the tablet drivers come with miscellaneous software for annotations and such that I doubt most of you will use. You get to configure the active area of the tablet and how it matches up to the screen, as well as any gestures to launch programs and such. The tablet driver is the Wintab type, meaning any applications that support the wintab interface work, that being the majority of them (Photoshop, Painter, Artrage, etc.). It does not give you the Ink capabilities of Windows Tablet Edition, nor does it give pressure support to programs that only support Windows Ink.
On Mac, UC-Logic's tablet drivers work with Leopard (10.5.2) all the way back to Tiger or something. Check UC-Logic's website to be sure. It's pretty simple. You don't get too many options, but the Ink icon will show up in Mac's System Preferences after you install it. Works as advertised.
On Linux, don't attempt unless you're daringly good at configuring X. They seem to present themselves as a standard HID device and the data from evtest looked correct, but for the life of me I couldn't get Ubuntu to recognize it correctly. It will function properly as a simple pointing device, with left and right click, so you can use it as a mouse, although the coordinates are a bit off-scale.
[Edit:] It's been a while since I tried it on Linux. Instructions for using this tablet on Ubuntu are at https://help.ubuntu.com/community/TabletSetupWizardpen