My Lenovo A1 tablet was running a custom CM7 Android 2.3 version but I was really curious to try the new ICS 4.04 version. After reading some really detailed guidelines I decided to download the files described and with my previous experience on flashing my tablet (it proved to be really useful) I managed to flash the ICS 4.0.4 correctly, and started installing apps/setting up the tablet. It took me quite a while to be able to correctly complete the process, mostly due to the downloaded files, which seemed to be corrupted every now and then. I also managed to flash the wrong file at least twice (among other mistakes I made), since I got confused with an evergrowing files named update.zip after some time and the fact that my laptop does not feature a card reader, so I had to work with my netbook as well.
So far so good: I am still getting used to the new user interface and setting up my tablet from scratch. The operation is smooth, with no noticeable lags and some new features are really helpful and look like a significant upgrade (like the mail client and the creation of shortcuts at the home screen). I will post screenshots as soon as possible.