I have been a die-hard 38mm supporter in the forums. I have 150mm wrists, smaller than a credit card in width and thought there was no way the 42mm would look right. I'm only 5'8 and barely 130 lbs. However, I went to the store yesterday and tried both on (sport) and found it very hard to decide. The dilemma as I see it is that most watches I would wear are around the 42mm size, however I'm not sure I want a gadget that large on my wrist (watch yes - but gadget?) My girlfriend remarked that she liked the 42mm but when she was across the room she could even see what was happening on my screen and it was like I had a toy on my wrist (we are both huge apple fans). I'm in my late 20's and the 42mm just seems to scream gadget, while the 38mm does seem a bit small. I'm still not sure what I'll do (though I have 38mm on order). I would encourage everyone to go to the store before committing...people kept saying it, but I didn't listen.