I brought SPB Shell 3D last month having been using launcher pro before that on my SGS2 and N1. I find it the smoothest experience I’ve had in a launcher. With LPP I found that I could have 5 home screens filled and keep it fairly fluid. With Shell 3D I now have 9-10 and its somehow smoother.
The carousel is really pleasing on the eyes if you go with all black, not a massive amount of use but if you have 10 plus screens it can be quicker for navigation once you start using it more. Again super fluid 100% of the time.
The widgets included are good; the animations on the weather for example are subtle but well done. The folder system is the best I’ve had on android and the way home screens are reorganised to make room for additions is something Google need to have a standard because it makes so much sense. There is even a little buffer zone where if your screen is full, icons/widgets will drop off to the buffer to accommodate the new item, and will change back if you remove it -awesome!
There is still room for features we have come to expect from Go/ADW/LLP. Customisable dock, hiding apps in the drawer, homescreen looping, restart launcher etc. The memory foot print is pretty big I've seen it hit 80mb, wouldn't surprise me if it passes 100mb at some points.
I have compromised a little the way I like my launcher to look, like having to have a 3rd party app drawer as I hate it unorganised but in return I am getting alot of positives.
The price is relatively high and more advanced features are needed in the long run but if you take this as a work in progress the speed and shine of this launcher take some beating. in its current version I give it 8 - 8.5 / 10