Cobalt XF Chrome 4MM High Polish Plain Dome Wedding Band Ring for Men - Durable & Hypoallergenic Tungsten Alternative - Perfect for Engagement, Anniversary & Everyday Wear

Pros: Very high polish, quick shipping, creative and tasteful ring boxes, comfort fit and can be resized by jewelers.Cons: Scratch resistant, not scratch-proof, a little too wide with no 2MM option and rather thick compared to other rings.Very impressed with the look and feel of the rings, they're very high polish and have a nice weight to them, while not being as heavy as tungsten rings; although the lack of 2MM band is a little disappointing - it is somewhat on the wide side if you have small hands. Rings are also rather thick, maybe a bit over 2 millimeters, so combined with the high gloss color, they stand out quite a bit on your hand and can hurt during handshakes (not that you would shake hands with your left hand often, but it happens). The color is basically identical to white gold or platinum, not nearly as dark as tungsten.What I, however, found rather disappointing is the low scratch resistance of cobalt. Having done quite a bit of research prior to purchase, I was aware that, being a metal, cobalt isn't as scratch resistant as it's ceramic counterpart - tungsten. I was, however, quite disappointed to see as much as half a dozen of small nicks and scratches appearing after just a week of very gentle wear (by which I mean wearing it on vacation - no sports, no manual labor, no kitchen work, not even computer use). I've discovered that sometimes they can be buffed out with the velvety cloth that comes with most glasses (meaning that those are probably smears left by other softer materials that the ring came in contact with), but a number of scratches are definitely there, in the metal, only after a week of careful wear. If you work with your hands a lot and want the ring to stay shiny, you should probably opt for a ceramic ring.Only one other thing to note about cobalt rings, from my pre-purchase research, is that these can be quite difficult for a hospital to remove in an emergency (it takes about 10 minutes, 5 minutes per side since these can't be bent, to cut through a cobalt ring with a diamond saw, if you need to be taken into an MRI machine or something), while other softer metals and shatterable ceramics can be removed almost instantaneously. So make sure you don't pick a ring that is too tight on your finger, if that is a concern for you.TL;DR: Great looking ring, very bright and high polish color, a little on the thick side and does scratch (but not nearly as bad as other metals and still can be polished by the jeweler).EDIT (October 17, 2012): After wearing the ring every day for a couple of months now, I have to say it stands up quite well to major scratches. Sure it still gets minor nicks and abrasions, not unlike the ones obtained in the first week, but they are not noticeable from the distance so overall it stays smooth and shiny. There is absolutely no comparison to white gold jewelry, which becomes nearly matte with scratches after about the same period of time. In fact, I will increase my original rating to 5 stars, this thing wears great over time!