I just got my wheel covers today for my 2012 (the dealer had them on the lot without the covers with the added toyota center cap), I had to go back today to get the covers, and IMO I think it looks much better with the covers. I like how the black of the actual alloy wheel outlines the cover and gives it a 3d look. I guess I am old though. I teach high school and all the kids seemed to like the black wheels. It just seems it made them look smaller.
They were chrome. I didn't get them back - unless they stuck them in the back. Should I have asked for them back? They were not on my invoice - it said wheel covers.
I have the wheel covers on now. I didn't know what they had done with the chrome toyota center caps, however, they put them in my storage compartment in the back. So I do have those, although I don't plan to ever use them - I really prefer the look of the wheel covers.
I test drove a silver '12 that did not have the covers on. My wife and I both liked the way it looked, the contrasting color scheme from the typical 'boy racer' look of black car/chrome wheels. Wound up getting my car in Nautical Blue, and may go the cover-less route and install black center caps soon enough.
In California that is the boy racer look. Blacked out wheels are what they call a "tuner look". A great many larger lifted trucks in the area run black wheels also. Around here it is played out. Hopefully it's not in your area..