I have them both if you've got any questions in particular.
I much prefer the JBC because I can adjust the temperature (without buying new tips), this is only for hobby level stuff like rework so the temperature flexibility is more useful especially when dealing with really crap quality PCB's that lift pads when you breathe on them.
Here in Australia the JBC tips are only a little more expensive (fx-100 hakko tips are unusually expensive due to rarity), but I think in the states its more like double to triple the price. The JBC tips are known to not be that durable but that's the price you pay for excellent thermal capacity...
I use the JBC 100% of the time, I only got the Hakko because it was for a price you couldn't refuse. I only use it for when I need two irons to desolder PCB mounted heatsinks chopstick-style.
If I were in the USA, I would look into the new-ish Pace ADS200, it seems like really good value.