Word is Swaro customer service is second to none
When I first got my SLC's, one of the bushings in the twist-out eyecups came loose and wouldn't stay where it was supposed to. I called their customer service, and they apologized for the inconvinience and sent me a replacement eyecup. They were very helpful. They have been trouble free since then.
If I had to do it over again, I'd probably wind up with another pair of Swaros.