We've been to Oroville area near the Canadian border. IMO most anyplace along I-97 from Wenatchee north. It's hot, dry & desertlike in the summer yet there are places with scattered trees and greenish areas-mostly the domesticated areas along the Columbia River. And I've
heard it can be very cold & lots of snow in the winter (I don't cross the mountain passes from October to May, so

)
I do love the look & feel of No Central WA, but it also has it's downside. Wildfires are abundant nearly every year and alot of them are difficult to contain due to less populated areas/lack of facilities.
We were in Oroville a few years ago during the massive Okanogan fire that destroyed 10,000+ acres. It was scarry since we were only a few miles from it. The smoke blocked the sun and ashes were 'raining' down on us. We were far enough out of town in the hills with no communication reception (tv, phone or radio), no nothing.
We did see some guys from the fire dept start some work near the only road in or out of that area and I asked them if we needed to evacuate. They said 'not yet' but got another call to go to Omak and had to leave.
Anyway, another downside is the job market where farming/ranching/orchards prevail there are others but in more limited supply, although Spokane area may have more options.
Please do understand that my knowledge of the Eastside is limited, since I don't currently live there, nor do I know anyone who does and my actual experience is a few summer trips usually in the sweltering 110 degree August heat. I suppose if I did ever live there full time/year round, I may not like it so much. :/