I've had a 125i convertible with a 6-speed manual transmission since last year. It is exactly the model I wanted and really a car that makes you happy :-)
But there is nothing that cannot be improved. Already in the test reports it was criticized from time to time that the 6-speed transmission is a bit difficult to shift. That is exactly my impression. I'm not used to this from my previous E30 with 5-speed gearbox.
Now I wonder if you could make a difference by changing the gear oil. Perhaps the type of oil also plays a role. The car is from 2008 and has 93,000 km.
If anyone has any experience in this direction, I would be grateful for a tip.