Still room for improvement, on my experience.
Google maps had all the streets in our area wrong. In September 2009 I went through a laborious process to advise Tele-Atlas of this. The other day (just 620 days later), I received an acknowledgement that they had acted on it. Click to enlarge.
A less than inspired piece of customer experience, I think you'll agree.
However, a look at Google maps with a 2011 tele-atlas copyright shows no change.
Multimaps (now Bing) still has it right.
(Openstreetmap doesn't have any of the streets as yet - perhaps I should have spent my time helping that). This looks like a suitable application for 'gamification'.