SoCal to east side of North Cascades: 395 or 395/97?

Other than the section of 395 between John Day and Pendleton, I suspect that you'll find 97 more interesting overall.

Heading north on 395 from eastern California, I usually take hwy 31 from north of Lakeview to LaPine.
Sometimes, for a change in scenery, I take 139 out of Susanville to Klamath Falls. But this route will take (quite a bit) longer.

Hope this helps.