Pros: Marks a ball as well as any other marker, can easily be flipped over so you can remember when you moved your mark for an opponent
Cons: Does not agitate my playing partners like my Yankees mark does
I recently received the WarSpec Spec1 Black Oxide ball marker for the purpose of writing a review.
My marker came with a little sight line cut into it and my initials etched into the bottom side of it.
The nice features are the curved front edge that fits nicely around a golf ball and being able to flip the marker over when you move your mark, so you will remember to move your ball back to it's original position. The sight line is also a nice addition, but I did not find much use in it since my golf balls already have an alignment aide on them.
Additional (less important comments) would be that the marker did not seem to effectively stop a ball that hit it and It was very easy for me to find on greens that are the correct color. It is more durable and better looking than the cheaper options out there.
If you can afford it, this would not be a bad addition to your golf bag.