[speedo]

i had the same dilemma. i chose the sub-c because it's less flashy and in your face then the bezel of the gmt. i've been wearing it for a week now and none of my colleagues commented on it. i reckon they'd have noticed the gmt.
i'd love the gmt function on a watch but the pclessness and the clasp of the sub just sealed the deal for me.
of course if you plan to buy more watches or have several others, or you like more flashy pieces, the situation is different. i was looking for a watch i'd surely like 20 years from now.