I did a 3D model for a friend and it needed to be printed in metal, so I sent it off to Shapeways.
The results are, it's not bad but definitely not up to being used as a replacement for machining, but I think we will be able to use the piece, after some rework.
There's a small vent hole in the top which was closed when I received it, but it appears it just wasn't broached well, a small drill cleared the printing powder easily.
The OD of the original was 14.18mm. The printed object is around 13.9mm. The ID was set at 6.09mm, the printed object varies from 5.95 to 6.09mm. So in general not bad at all.
The surface is fairly rough as you can see in the photo. It'll probably do for this application, though.
The material is quite hard. Drilling it out round is pretty difficult.