How good? Potentially cross-loaded carabiner and the thread relying on a small neck of rock that looks as though it could easily fail.

Probably better than nothing, good try!

Reasonable question John. It's rare to find threads in igneous rock and always nice when they present themselves. Just below this was a good cam and above a good nut placement, so actually the thread was an afterthought (I was just a bit excited to have found it)! Still, I was happy with this placement and it has the advantage of being multi-directional. Yes there's potential for cross-loading, but unlikely as the 'biner would more likely straighten up under load. A cross-loaded DMM Sentinal is rated to 10kn, so pretty strong. The reason for the screw gate was to help eliminate the carabiner unclipping itself from the wire.