I've been having the same issues and finally got the SII to sync via wifi with outlook.
The main issue I have encountered is that "loading" takes 10 minutes.
It is TOO LONG... I am worried that power saving protocols on the phone may break the connection before it has finished "loading".
I have a 32GB SD card, half-full with a few movies. Perhaps I have too much memory.
I have all antivirus-firewall deactivated. Once I can get it to connect via wifi repeatedly, I shall activate these and see if they are a problem.
I have just had it connect again, it took 9 minutes, from 11:17 to 11:26.
In addition I have toyed with WPS on the router and gone over the network and service configuration as stated in the samsung tutorial. Most of them where correct on the 3 PC I have tried.
8 minutes to "load" is too long... On USB cable or with Kies Air it is instantaneous...
At least I have "seen" the smartphone sync to outlook :-)
I feel the purpose in my life has been fullfilled...
Now I can continue to sync via USB :-)
P.S: Kies Air does not sync. I repeat, Kies Air does not sync. Kies Air CONNECTS your device to the PC via the web-browser, allowing you to manage the information in your phone, but without the posibility of syncronising with Outlook and other programs.