I've owned and loved a JLC Geo for years now, and lust after the Lange world timer in PT or RG. I'm not a big Lange guy in general, but there's just something about that particular watch that grabs me.
I've also owned a Reverso Duo -- also a great watch, and a different take on the "two face" model. One neat thing about the Duo (and Reverso GMT) is that a single movement operates two sets of hands moving in opposite directions -- while keeping the minutes synchronized.
One thing about the J**D -- I like the watch a lot, but it only has twelve city names, not including any in my time zone (U.S. Pacific Time). All twelve "hours" are represented, but not all 24 time zones. I forget the exact city that's 12 hours from San Francisco (maybe Dubai?), but I found it odd not being able to have my home time properly labeled on the watch.
Have fun! Sounds like a great search.
Best,
Gary G