It's slow to the point of being painful to use, never mind actually pleasant. I know the refresh rate is always going to be crap, but there's no reason we can't get half-decent internals alongside an e-ink screen.
Is the Oasis performance that different than the Paperwhite?
I personally am less concerned with closed-platform reader technology, and more concerned with closed-platform content. If a reader will let me sideload my open content, I'm reasonably okay with it. (Yes, I acknowledge supporting such an ecosystem is contributing to the overall problem.)