Downsized from a Buick Century for economical reasons and am very pleased. The comfort & handling of the Matrix is beyond what I thought it would be. I am very satisfied with the 1.8L engine, it's enough for what I need, it has enough pick-up for passing, etc. Responds very nicely, turns tight corners, easy to park. Loved the colour choices... we picked charcoal gray.
The over all look, the dash (the huge glove compartment & all the nooks & crannies). Heated side view mirrors, and the head/tail lights. Actually, the Matrix had a lot of features my Buick had so I found that very attractive when shopping for a new car. Slick little beast!
One major thing would be to have a shift-lock for the automatic transmission. Regarding where the shift arm is located, I accidentally knocked it into neutral while driving. And for my size, the rear view mirror does block my view. Nothing else comes to mind.