Since so many people here have not really answered the question, except to either say they like or dislike it, here is my own feeling on it. For starters, the implementation of "Wireless Charging" can be handled in different ways. The Galaxy S3 and other devices that have support within the device means that you only need the back cover to include support for it, no special cases are needed in this case.
So, with induction charging(what people call wireless charging), you just place your phone on the charging pad, and your phone will charge. No docking connector or anything like that. As a result of the lack of using a physical connection to the phone, you never need to worry about the connector breaking, or wondering if the problem with not charging is caused by the cable. This lack of needing to worry about breaking the physical connector over years of use is by itself a very nice benefit that should not be ignored. It does speed the process of taking your phone off the charger compared to the normal charging methods as well.
The real issue that many seem to feel is that since the back cover that comes with the S3 does not include support for the charging pads, people don't want to pay a lot of money for the back cover PLUS the charging pad.
Now, on the plus side, if you get a back cover that supports the Qi standard, you can get the charging pad of your choice, and are not limited. This is the key difference between the Touchstone version you see people talk about, and the Qi version. Qi is more "standard", while Touchstone is limited to working with a part that is no longer made. Also, I've seen people mention that they don't get the full 1 amp while on the Touchstone, while a proper Qi implementation would make using the wireless charger work as well as plugging in.
Until you try using it for a few days, it almost seems like it is just a marketing tool to include support for it, but really, once you have it, you realize how much you hate having to use a physical connector. I miss it from my Palm Pre days, but want to go with a Qi method, so have been looking for something cost effective.