Acura TL vs Nissan Altima?

Im currently been saving and am now ready to purchase a car. Im either looking at a used Acura TL 3.2 between 2004-6 or a car I have had once before a Nissan Altima. I look for a few things in a car but the Acura TL models seem to favor me. What are some issues that I should look into before purchasing this Acura TL.

Had an acura once in college, an MDX. I like luxury. and the TL seems like a fair for me. The altima i had also (05) in college. sold it and it hurt. So ima trying to figure out which car to go with. I'll take the TL if i feel as though the investment is worth it. What issues do the Acura TL have and milage do you start seeing issues.