The only quibble I have with with a San Jose - Portland daytime service is the length of the trip in hours and what that means for the departure and arrival times at each end. The Starlight currently takes 19 hours (via the Natron Cutoff), so you'd be looking at a very early AM departure from the origin points, with late evening arrivals at the other end. I get it that very few trips would be end to end, but I would think you'd want the arrival and departure times in the major population centers to be a little more convenient.

My two cents.