Up front - this is an entirely personal decision, but as others' opinions were requested, I'll chime in...
Assuming you were the original owner of your X3, you know exactly what it has been through, and you indicate you have had zero problems. You have a good color combination for Florida, lighting package, and only 8K miles. The G01 is coming out most likely one year from now. $41K seems like a sizeable amount to upgrade to the 35i, but it is adding a hitch (have no idea how important that is to you), slightly lower finance rate (I haven't done the math to figure out how much each month) and tech package, but black on black in the Florida sun - suppose you can use windshield reflectors and/or add window tint.
If it were for my family, I would hold out for the G01 when it is released (although realizing our three X3s have always been 35is) - as the G01 should be an amazing update to what we all have now. And once it is released it would seem there should be some fairly good incentives on left-over 2016s if you decide to end your lease early.
Good luck with your decision.
