I do some work with the Samsung phones. They're decent. I don't mind having an iPhone as my personal device though.
My last Samsung device was the Intercept, which was basically a slightly better version of the Moment. My experience is that Samsung makes top-notch high-end smartphones, but if you look at the mid- or low-range, they suck pretty hard. Underpowered, underperforming, unfriendly.