Anyone using regional/city targeting in google adwords- US only?

I'm experimenting with both regional and non regional ads for adwords.

All ads are exact match for keyword phrases. The keyword phrases include a lot of keyword phrases with the state name before or after the keyword phrase or the two letter state initial before the keyword phrase: ie New York blue widgets, New York widgets blue, NY blue widgets, or NY widgets blue.

I've targeted these ads - using local parameters for about 1/2 the population of a state.

Then I've run the same ads with exact match on a national basis. On a short term basis there seems to be dramatically more impressions when running this nationally.

I know Google and others have identified that local parameters may be imprecise due to IP addresses. After 2 days total impressions were about 5 times the average for the targeted local parameters. CTR's are about the same.

Just curious who is using local parameters and what their experience has been to date.

Dave