Yep, I never felt like I acclimated to the altitude. I never felt it exactly, it wasn't a sense of not getting enough air or anything, it was just that a four hour hike had me feeling exhausted. I reminded myself I hiked for thirteen hours last December in tougher conditions (but half the pack weight) from 1800' to 4800'. I don't think it was just being a bit wimpy, it was a physiological response.
If you have any suggestions for 8-9000' peaks, I'm all ears! I do want to explore the PNW, but it was off the list here in May because I didn't want to deal with changing winter/spring conditions.