Welcome to United Bimmer.
Good to hear you finally made the switch over. The engine and transmission is very well built. It had a few flaws such as plastic cooling system components. But you have many hundreds of thousands of miles left on the engine and drivetrain if taken care of. Contrary to what people say, you should change the transmission fluid every 50,000 miles. The actual manufacturer has never ever stated not to. That was a marketeting gimic by BMW because they made more money off of replacing your transmission then just changing your fluid.