I bought SGS2 last sunday 7th Aug 2011. Used it extensively checking every minute details of the phone.
Problems:
Second day 8th Aug, I went to office. Started showing it to my friends, then suddenly, screen went blank. Thought I did not charge the battery and put it on charging.
Again in evening same issue. I took the phone to UnveriCell Hydernagar (from where I purchased). They formatted (I had to backup my photos which I proudly took) and gave it back to me. The store manager (Mr. Santosh) told me that if the problem is repeated he will get me replacement piece.
I was attending some calls but the time I reached home again same problem. I did not waste any time as the store (UniverCell) was about to be closed it was 8:50pm. I called up the sotres and informed them that I am coming and returned the piece.
I am waiting for replacement hope it will work.
Will update you all on this further.
On 12th Aug: The UniverCell people got me new handset. Its working fine, and I did not observe any problem with it.
I have downloaded couple of applications from Android Market application. The speed with which all the applications work is really good.
One downside is I had to charge batter everyday almost, must be because I am using it almost 8hrs a day.
22nd Aug: No problem mentioned above. The phone is simply superb with awesome speed. If you have good bandwidth BB then you should see live streaming, and otherdownloads. Its like ZAP.
23 Oct : No issues what so ever. The phone rocks. Its neighbbours envy and owners pride.