No problems at all. I never use anything else.
I've also stopped padding the loops. I do always use overlays though. Might make a difference without overlays (although I doubt it), but there's just no way a string with 200 or 300 lbs of tension is going to cut into a hardwood, bone, antler, horn, or phenolic overlay.
Actually scratch that, I don't always add overlays. I've been shooting a 50# mulberry recurve without overlays for some time without incident. The string groove does not cut into the back though, only sides and belly.