When I was in highway traffic this past weekend in my '12 Q5, I noticed that when I slowed down to about 20km the transmission seems to struggle a bit switching into the lowest gear. I dont think its anything serious but the vehicle seems to experience a little hiccup as it gears down. This never happened in our '08 A4.

Any thoughts?

 

You're not alone!
Some Q5 owners including myself have the same problem.
Mine downshifts roughly when going from 2 to 1.
There are software updates available, but only applicable to some.
But you could always ask for a manual adaptation configuration.