I like the Thule Aero bars for their style and functionality. The rubber strip that goes along the top will provide good friction if you use your bars to carry something without a specific rack (ie. a ladder). I didn't notice any whistling or wind noise, but I have them on a 2010 Jeep Liberty which isn't exactly aerodynamic.
My big complaint is that many of the racks that Thule makes don't use the integrated slot load feature. The idea is that the racks clan slip in a slot under the rubber strip and eliminate the need for clamps around the bar. Since this feature doesn't exist at all with other rack systems, I can't complain too much. Hopefully Thule will use the slot more as they redesign their racks.
All in all, I'm happy with the bars, but you'll have to decide if they are worth the extra money. I've got chrome side rails, so these match better than black bars.