I don’t like the new custom-coloured status bars, mainly because it makes the text in the bar harder to read, as the traditional contrast of gray-on-black is lost. This is my number-one complaint with iOS 6, and I sincerely hope the ‘feature’ is removed by final release.
For example, see this comparison image by iMore. The white-on-blue status bar is difficult to read quickly, as the colours are too similar in contrast.