Got my SGS2 ICS upgrade via Kies (UK Orange). Looks good and everything seems fine so far. If you do it, though, make sure you know how to set up your Orange tethering APN as I lost my tethering until I set the extra APN up again, and it took a bit of hit and miss playing with the settings. Face recognition unlock a bit weird, but seems to work. Let me into my phone, but not my husband. Ha ha.
Until I've tried all 96 apps, can't confirm it's all perfect but so far so good. I've had ICS on my eee Transformer for a bit and it behaved fine, so I wasn't too anxious. It's definitely a very pretty interface.