The Sun Moon in steel is going to be very popular for good reason. It's a beautiful design IMO. One of the enhancements of the Sun Moon is the wonderful double deployant which comes standard on the strap. No more flipping straps or having to buy a non-OEM deployant (I did both w/ my RG GMT).
The RG GMT is very functional even for the infrequent traveler. It's a travel watch for someone (like me) who wants a travel watch that doesn't really look like a travel watch or world timer.
I am not a big fan of bracelets in general but the RG GMT looks better to me on the JLC bracelet than it does on the strap. I wore it on the strap for a year before I bought the bracelet. I have a small, flat wrist so the lugs extend to the limits of my wrist making the strap drop vertically. The strap attaches at the very end and bottom of the lugs so there's a little gap between the strap and the case when I wear it. However, the bracelet fills the gap completely and gives a very uniform appearance. It also makes the watch look a little smaller on my wrist. I'll try to take a wrist shot when I put the bracelet back on.
The bracelet is comparatively expensive but really looks good (plus I can wear it in the hot, humid summers here). I suggest you consider the bracelet or better yet, get both either now or over time.