Welcome welcome. I guess gearbox problem applies to most if not all makes of cars. After many years of usage, the gb will surely need some repair/recon job.
I'm sure you've heard how some japanese make car with CVT gb suffer after only few years of usage.
If you're sensitive to gb issue, I recommend you get a manual tranny BMW then. I know it's rare and not easy to get one.
Looking at your age and the car you own (or used to own? RX8) I'm sure you're on the 'rempit' side hehe. So I guess manual tranny would not worry you so much and moreover it'd save you $$ in terms of future maintenance, if you intend to keep your BMW for a number of years to come.
My $0.02 worth.
Cheers.