I don't have any experience with the Obsidian package, but I know the 10.6 are said to be very good speakers.
Do you plan on using subwoofers? Looking at the specs alone of the Obsidian towers doesn't give the whole story. Showing them to be 30Hz capable without giving whether this is -3db or -9db down, isn't helpful. It could be that these speakers do in fact play down to 30Hz, but at a level in which it's not very usable. Also considering the fact that built in subwoofers in tower speakers are almost never in the correct location in the room for a subwoofer, you're probably not getting very satisfying bass from them.
Now, the 10.6 are very nice speakers. Especially for the price. The midrange and highs would most likely be an improvement. The bass may or may not be, depending on how well the Obsidians perform.
Is there any way you can try the 10.6's out in your home? Doing a direct comparison would be the best way to go.