Savvy frequent flyers avoid small aircraft operated by regional carriers when there's mainline service to the destination. The reason is that when weather forces a slowdown of takeoffs and landings at either end, the mainline carriers have to choose which flights are delayed or canceled. And they will always first target the small aircraft flown by regional partners as they impact the fewest passengers and don't impact the mainline carrier's crews. If I were traveling SJC-PDX I would stretch to choose a nonstop, including looking at OAK-PDX and SFO-PDX as alternatives, before accepting a connection. I would also prefer to fly mainline service, like Southwest out of SJC/OAK or United out of SFO, instead of some big airline's regional partner.