Wow! Portland to Atlanta. We're from Philly and have lived for extended amounts of time in large and dense cities like Tokyo, London, and Melbourne. ATL has been a huge adjustment for us. This is a car city, through and through. Traffic is almost next to impossible to avoid---everyone here, including the baby, owns a car. You will rarely see more than 1 person in a car on 85 or 285 (huge generalization, but it really does feel that way). Neither one of us have ever had to drive until we moved to ATL 4 years ago, so we decided to stay Intown (or as people here call it: "Inside the Perimeter"-ITP)
Decatur downtown is adorable and it is actually ranked the most walkable area in all of Georgia. Yes, in all of GA. The nearby neighborhoods of Oakhurst, Edgewood, Kirkwood, Candler Park, Inman Park etc. have so much to offer in terms of mom and pop stores, good food, unique coffee. tea shops and music venues. Near Decatur is Stone Mountain---plenty of park space to run and climb. And the DeKalb Farmer's Market is huge and way cheaper than Kroger/Public for produce and meat (spices are cheaper in Indian market stores on Lawrenceville highway). Close enough to Decatur is Clarkston---and if you love Somali food, Nepali, Ethiopian---this is where you need to go- a majority of refugees place in ATL are resettled in Clarkston.
In a nutshell, please don't believe that ITP is full of crime and blight. What that person means to say is that these areas are DIVERSE racially and economically. It is eclectic, happening, and relatively close to Atlanta downtown -which we wouldn't really recommend to live in since it seems like nothing is ever really happening downtown...but the High Museum of Art is fantastic and the Aquarium is unbelievable.
That said, Decatur, Avondale, East Lakes etc. are not cities the way we use the word city in the Northeast. They are suburbia, at least to us. There are lots of small families and young singles. If you really like art/music/semi-urban you should look at the East Atlanta Village (EAV). With your price range, you could find a really awesome bungalow or craftsman or Charleston type house that would be close to the farmers market and shops. EAV is smaller than Decatur though, so that's what made us choose Decatur.
Outside the perimeter is just suburbia ranging on boredom---lots of cookie cutter box shops. You have to drive everywhere and yeah they have parks...you gotta drive to those too.
We have no kids---but 4 cats plus 1 dog and we manage just fine Intown. :-) And yes, public school rankings and access to private is HUGE here (probably b/c GA as a whole is a terrible state for education). Take that into consideration when choosing a place to live (for reselling).
Hope this helps and good luck!