Yup. Couple times now. If it's just for sharpening, send it in a box with $5. It'll take 'em 2-4 weeks to get it back to you, but it'll be nice and sharp. They'll also check it over, clean it and lube the pivot for you.
Last time I sent mine in, I thought they'd need repair, which comes with a $20 fee. Sent 'em in with $25, I got them back with $20 and a note saying that they only needed $5. I'm pretty happy with spyderco's sharpening service. [emoji2]