After reading a lot of comments on the coasting thing, I think it's only available when you have the
Driver Profile Selection package, and it should prefer to coast more (or always?) when the profile is set to Eco. Even though mine is a style trim (the highest in EU) and with R-Line package, I don't have the Driver Profile Selection feature and mine never coasts.
And on topic, yeah the DSG really likes to shift early to conserve a few drops of fuel. I think there's nothing wrong with that, I just wish they worked a little bit more to counter the vibrations. There's nothing you can do apart from driving a little bit more aggressive, or switching to S.
I don't think the DSG has long-term "learning" like older automatic gearboxes. I find this to be an old and flawed concept. The DSG does a lot better job to react to what's currently going on (position of throttle, whether you are on incline/decline, whether you are decelerating from hard acceleration). I have found mine very predictable (and I have driven it a lot) and always reacting consistently in the same circumstances.
What I don't like at really low speeds is when it suddenly downshifts from 2nd to 1st because it's usually very harsh. Also I had few cases of kangarooing in the 10mph range few times. I thought only the 1.5 TSI model is affected by this, but apparently it's not an engine issue.