(Above taken with a crappy old phone camera)
Wow...what a phone!
My primary worry at first was the build quality. The moment I picked up the GS3, I thought "This is what everyone is complaining about?" To me, the phone feels solid, and the hyperglaze certainly gives it a more premium feel than cheaper plastic phones. I liked how slim it was, too. I did note that the screen size was just enough that it pushed the limit of being able to use the phone with one hand.
There were only a couple Marble White phones there (did not handle those, both colours will launch here), but I thought Pebble Blue looked quite good. That would probably be my choice. The Pebble Blue colour really divided people- some (like myself) found it to be refereshing. Others would have liked if it was a bit more black/grey. Also, I appreciated the physical home button, even if it was a touch small.
In terms of performance, this is a greeeeeeat phone to use! Yes, the screen is PenTile, but I barely noticed! It's certainly better than the Galaxy Nexus display.
The Snapdragon S4 with two GB of ram also make the GS3 quite speedy. I did not notice any slowness- everything seemed buttery smooth. Pop Up Play worked nicely (although it is a tad gimmicky), and I found S-Voice worked just as well as Siri in asking math questions, the weather, the population of London UK and the exchange rate for the Canadian dollar (my chosen examples). Sometimes, it would pick up background noise and say "I didn't catch that." The room was loud, though.
Smart Stay did not work well for me at all, though. I wear glasses, and I have a lazy eye, so I suspect that messed it up. The GS3 would sporadically show the little eye icon recognizing I was looking at it, or just go to sleep even though I was looking right at it.
S-Beam works like a charm (tried it with photos, only took a moment) and they say you can transfer a 1GB movie in three minutes. Regular Android Beam also works with non-GS3 phones.
The camera seemed to work really well. I was impressed with how well Best Shot picked out photos that were in-focus and well lit.
Little touches like the range of gestures made the GS3 a joy to use. Overall, I thoroughly enjoyed my time trying it out yesterday, and I know it will be my next phone!
I think the option of expandable memory alone makes the GS3 a big winner over the HTC One X. While I agree with others the GS3 may not be worthy of innovative design awards, I think the build quality is quite good.