Agreed they are both nice drives. Are you planning on stopping part way or driving straight through? If you stop, that might be your determinating factor on the route. We regularly drive down to AZ to visit my folks. Lately we’ve been doing our ovenight stay on the way down in SLC, and we take the former route you described. I’ve done your latter route on my own and stayed in Twin Falls, ID (continuing down thru NV to AZ). Personally I don’t care for the drive between here and Portland due to the traffic spots along the way. But the drive along the river is lovely once you get there.
