Junebug, I understand what you're saying about TicketMaster, hehe. If you're forced to wait until the day-of, you'll have a better chance at the Box Office than online. I think what happens is there's floor tickets reserved for VIPs, radio station promos, band pool, etc, and throughout the day, these people realize they don't need them all and turn them over to the venue for drops. I'm not sure how it works, but I've heard in situations like this, the venue will have access to more ticket drops than TicketMaster as a whole, so you're better off getting to the Box Office REALLY early than sitting at your computer.
Good luck! I drove over 8 hours to St. Louis in the dark and snow/rain and had to wait until 3:30pm the day of the show for a GA ticket to drop! 7 GAs dropped in the morning, but I wasn't first in line. Of course I was first after those drops happened, but then nothing....for 6 hrs...until at 3:30 they announced there would be a drop of seats. I wanted to cry b/c I knew I couldn't afford the seat and I'd driven all that way to sit in the car. So when the drop happened, I turned down the seat and said I just want one GA please and the lady tried and tried until I got one
It was veeeery stressful and if I'd had the money I would've much preferred to pay extra for ETS or a broker. The nice thing was they let us wait inside as long as we kept quiet, stayed in line, and stayed out of the way b/c people were coming to buy tickets for other events. Considering Portland will be in higher demand, I'd exhaust all other options before a box office drop, or at least make sure you're first at the box office.