Both the smart phones are very much the same in size. Galaxy SL i9003 is slimmer than Nexus S with thickness of 10.7mm in contrast to 10.9mm. Nexus S has over curved edges while Galaxy SL has a slight curvature. Again there’s not a lot of difference in weight of the two smart phones with Nexus S weighing 129g in contrast to 131g of Galaxy SL.
Nexus S features Super AMOLED capacitive touchscreen with resolution of 480 x 800 pixels and 16M color support. Galaxy SL has a SC (Super Clear) LCD capacitive touch screen with same resolution and color support as Nexus S. Nexus S has contour display while that of Galaxy SL is Gorilla Glass. The screen size of both smart phones is 4.0 inch. Although SC LCD is much better than other LCD panels around it is not been able to match the brightness and clarity of Super AMOLED.
Processor and OS:
Both smart phones have 1 GHz Cortex A8 CPU powered by Power VR GPU. Nexus S has a slight edge over its counterpart having the latest Android 2.3(Gingerbread) in contrast to the older version Android 2.2(Froyo) in Galaxy SL.
Both the smart phones feature 5MP auto focus camera with LED flash but Galaxy SL has a slight advantage over its competitor bring able to record HD 720p video at 30fps compared to 30fps WVGA recording in Nexus S. There is also a secondary VGA camera in both devices. There is also a face and smile detection feature in Galaxy SL in addition to common geo-tagging and touch focus features in both smart phones.
Nexus S has internal storage capacity of 16GB with 512MB of RAM. Galaxy SL is available in 4 and 16GB versions of internal storage with 478MB of RAM. The external memory can be up to 32GB via micro SD card in both the phones.