Just saw the galaxy nexus and s2 at the samsung display on Michigan ave. screens looked much better - beautiful screen, for the most part. Was reading the samsung mobile Facebook page that they have as a homepage. The text was notably LESS sharp than on my iPhone. Multiple sets of eyes confirmed it in a 1:1 comparison.
They just are, in the words of Ilya Bryzgalov, "humongous big". If there was a version in the 3.5-4" size like an iPhone, id really be into it. It feels less substantial/more plastic, but not low quality, and feels light in handling versus even an iPhone, and given its size.
It wasn't easy to navigate, maybe it was the demo mode or whatever, but the iPhone is more intuitive and seamless. I'm sure they are quirks that would be easily gotten over, but for now, need work.
Next generation, if they have a 4" version, it will be a real tough call, the Samsung phones are REALLY nice and good. It's just that if an iPhone is 95% of ideal, the Sammy is like 90%. If the Sammy's are $150 and $250, they don't really give a huge price advantage. I'm confident in my selection of the iPhone for now, but Sammy is integrating phones that are getting there. Not worth buying just yet though... IMO.