It seems like a good deal.
These are some reviews I found.
Here's a review from Technobrains.
"The Siso Tablo from Hantech is a great add-on tool for anyone that spends long hours on their laptop. I find using the stylus more relaxing over using my index or middle finger for hours. The quality of the materials used are good and the design is pleasing to the eye. The suggested retail pricing is $129.99 USD but I have seen some online shops selling the Siso Tablo for as low as $99.99 USD. The Siso Tablo is one accessory that will be around for a long time for me and is one I would recommend to anyone that has a Windows Vista based laptop currently."
And this is a review from Slashgear:
"The Tablo flawlessly interacts with Microsoft Office, giving users control of the program through the Tablo’s pen. Users can write on the screen and have the handwriting recognized, and also use the pen to control the cursor. The device uses a magnetically mounted sensor (which functions much like a Nintendo Wii) to detect the location of the Pen, and set up was quick and easy. It took about 30 seconds to calibrate the device after I installed all the software, and I was using it without a problem.
The best benefit of the Tablo may not even be for students or business types (though they certainly can use it), but rather artists. I had a friend test out the Tablo in her digital art class, and compared it to the other much more expensive design tools available. She found that the Tablo performed just as good as, if not better than the more expensive drawing tablets provided by her university. My friend was even more excited about the Tablo because the Tablo allows users to replace the felt tip with a ballpoint pen and draw directly onto paper, giving a textural sensory response when she was drawing. This is often the complaint about other graphic artist tools: no feeling of friction as the pen drags across the device, making it more difficult to control the pen. The Tablo eliminated that problem, and for a fraction of the cost of other comparable devices."
You can see how it works in this video.