As of now, I'm keeping mine. Then again, my days of trading in cars just to upgrade better be largely behind me.
I say "as of now" because I'll be keeping it barring any maintenance issues that push me away.
While not a fan of turbos, the turbo inline-6 is awesome in this form factor. The only thing missing is a manual transmission.
I like it better than the GLA and Macan offerings. Don't know much about the Q3 but I don't think it'd have anything that would sway me away.