I also love the sound of the 335 and the dual pipes out the back. The extra power is of course also nice.
Coming from a 6 speed manual 2008 335xi to a 2013 8 speed automatic 335 xdrive I like the ease and smoothness of the automatic but do miss the connection and precise control of the 6 speed manual. I miss not having to look at the display to know exactly what gear I am in.....I prefer knowing the exact gear I am in and gear I am going to based on where I shift the gear lever to. I think you are making the right choice sticking with the 6 speed manual since you seem inclined that way anyways