Not an AA, but I can give you my perspective:
Oregon has a history of both being very white and racist. At one time (in the 20's and 30's in particular) the KKK was very large and influential (in the 20's it basically ran the coastal city of Seaside -- all the elected officials and the sheriff.
There was a major incident in the late 40's called the Vanport flood.
There have been more recent incidents as well.
And I know AA who have come here from elsewhere and found it uncomfortable, mainly b/c there was such a lack of the presence of POC.
The traditionally AA neighborhood, North Portland has been experiencing gentrification and some of the tensions that come with that.
The racial demographic is shifting, mostly b/c of the in increase in the Latino population.
I think there are efforts to try and do things differently -- for example, w/the north Portland gentrification, there has also been attempts to foster dialogue among the old and new neighbors.
Personally, I live on a block that is probably about 50/50 white and AA.
So, I think it's a mixed bag, but I think it's also important to come here with one's eyes open. I know AA who have moved here and are comfortable and glad. I know ones who have left b/c -- not necessarily b/c of overt racism but b/c of the kind of unthinking oblivious kinds of bigotry that happens where there isn't a lot of people who don't look like you.
As for as the less urban areas, Oregon is like a lot of the country where a state has one or two very liberal areas, and the more rural you get, (excepting things like college towns) the more conservative it gets.
I think it would be worth it for all of the livability factors, but I'm also speaking from the privilege my white skin.
Something that might help is to look at local information like the local AA owned and focused paper The Skanner: http://www.theskanner.com/
Also, Portland has had 2 AA Chiefs of Police -- one Charles Moose, was highly respected and left to become Chief in Montgomery County, MD during the "beltway sniper" incident. The second, Derick Foxworthy was caught up in a scandal about using official email to talk dirty w/someone in the dept he was having an affair with. Now the CoP is a woman.
On the health side, the Hospital in North Portland, Emmauel Legacy has been a great supporter of the African American Health Coallition
which does a number of things to support health in the community, including things like training hair salon owners to talk w/their patrons about health issues, and other community based efforts. Their president and CEO , Corliss McKeever,
is an amazing woman.
I hope this didn't just muddy the water...