....that's exactly the ones which I hesitate for my new acquisition!
I'll go soon for the GMT IIc, but this is a personal taste.
Did you try both watches on your wrist? It could be useful because for me, I noticed that the JLC was too big for my wrist, and didn't fit right. But for the GMT IIc, it was perfect.
You have to try both of them and The One will be an evidence.