I love, love, loooove Portland! I've lived here about 10 years now and I wouldn't live anywhere else. (I've lived in/spent significant time in San Diego, LA, San Fran, Seattle, Cincy, Chicago, Detroit, Atlanta). I'm a city girl and like living close in. I work just east of downtown and live 4 miles directly north, so I can ride to work every day.
People here are very open and accepting, I've found. Most people I know here are not from here, so you'll be in good company. Business culture is a little small-town-ish. It can be hard to find a job here if you're not already here. We only have a handful of mega-employers (and only 1 Fortune 500 company based in all of Oregon), so it is a lot of small and medium sized businesses. Cost of living is average? Less than CA and Seattle, more than Boise. Really can depend on whether you live close in (higher cost) or in the burbs. If you live in the OR burbs, there is decent mass transit to get around, so that can make a nice trade off.
I seem to remember reading that, technically, Portland gets like 100 more days of sun than Seattle, but I think 5 mins of sun must count . Summer is nice, not humid, only a few days >90. Winter is usually not too cold, with only a few days of snow and ice (but still lots of rain). Spring is rain every day. Fall is usually nice with the rain coming in at the end.
Other things you should know - very green here. It's beautiful. We have great parks - Forest Park being one of my favs. Obviously, bikes are big here. No sales tax! Downsides - lots of homeless teens here, not sure why. Portland schools are pretty hit and miss, so if you have kids, Vancouver (WA, a suburb of Portland) might be an option to consider. High property and income taxes (see no sales tax, above )
Anyone else care to extoll the virtues of Portland?