19s will ride harsher and are more easily damaged when you hit a pothole. Depending on make, they may also be heavier, increasing the unsprung weight in your car (rule of thumb is every pound of unsprung weight is about equal to an extra 10 pounds in the car).
I've been researching wheels for a while, getting ready for a spring tire/wheel upgrade myself. I've decided to go with an Apex wheel, almost certainly the EC-7 in an 18x9 square setup. Apex wheels are very lightweight and strong (they are rotary forged, which is stronger than pressure or gravity cast), and look good. Some nice concave looks in both the Arc-8 and EC-7.
I have yet to hear anything negative about them, and the folks I know with them (some of whom have them on both street and track cars) love them.
Check the sponsor selling forum or their website, they have lots of photos of customer cars with their wheels.
2007 E93 N54