I have used the smartphone for a year before I gave it to my brother. Amazing quality and high performance smarphone.
I am not sure about the OS upgrades now but when I was using I did not get the updates on time (may be carrier dependent) but not to degrade the smartphone quality with that but something Samsung can take up with the Cellphone carrier .
I have had many phones in my time. Some of them would be hip but would constantly malfunction, and some of them would work well but would be so outdated as far as the availability of a wide variety of apps.
The Samsung Galaxy S II is the perfect marriage of functionality and entertainment. I can do absolutely everything with this phone. The Play Store has all the apps I'd ever need and more. The phone itself is highly customizable (so I never get bored with it!) and easy to organize.
It offers all of these things while also maintaining its functionality. I've never had an issue with texting or with phone calls. It works all the time, even after having dropped it on hard surfaces on a few occasions. (I have since obtained a case for it to avoid any more cosmetic damages, but the phone still works like a charm!)
To put it simply, this phone is probably the best phone I've ever had.
I recieved my phone a few weeks ago and started setting it up like my old HTC, I even bought a new 32gb memory card. Well I started loading files (music and movies) and the internal 16gb became full, I tried copying and pasting files to the 32gb card and they wont load for some reason. Thinking I may have a bad card I tried my old 16gb sd card with the same result. I'm not sure if I have a bad phone or not, but this is not satisfactory.
Pros: Built-in speakers, Bright display, Inexpensive, Realistic color
Cons: Did not meet expectations, cant add files to sd card.