Been going back and forth on this one. The write-up in ARG is pretty thin, but the SRD has a more expanded take which points to Strix and their 'human hatred' as being more that of encroached-on native inhabitants than an inherent evil.One thing I think we should do is rule against traditionally-evil races as being approved for PC use. So:
I also think the (new?) Strix fit this bill as well.
It's a Golarion-specific flavor, but I think something similar could work well for E'n. The Seithr need more than just the dwarves, anyway, and I'm kind of digging the idea of Strix Aeries high up where humans aren't comfortable, perhaps with a Strix/dwarven affinity, since the 'diggers' don't threaten their preferred territory.
Mind you, my enjoying the fluff doesn't change the fact that I'm not keen on an automatic 60 ft. fly speed at first level. If there isn't fluff-based objection to the race, I was thinking a good compromise would be to require PC Strix to take the Wing-Clipped racial alt.