I had he spur one and let me tell you it turned out it is for looks only, never put it in your pocket. I did and if something hits it, you will find out what a spur is like.
I like the Tom Thumb bit (how much I hate those darn bits) because you ony ever see jewlery and things like this made from D-ring bits (and maybe a loose ring or a full-cheek), and never western curb bits like this.