I have never had it, but even the cows tail makes a great ox tail soup...
Several years ago, we spent a few days in Chicago and ate at a very upscale restaurant. I had ordered a thick veal chop and the sauce it came with was scrumptious. I gave my compliments to the chef, who proceeded to come out and chat with us. He had braised an ox tail and then made a reduction of the juices for the sauce. It was meaty and rich and I can still remember the taste. It perfectly complimented the mild veal.
However, I think today, you would have to have access to a very upscale butcher to even get the ox tail. I have since googled the recipe and I gather the tail is actually the coccyx bone with the surrounding flesh. I think they use _some_ of the actual tail itself, maybe for the collagen?
Come to think of it, I know someone who owns a meat locker and butcher shop. It is a friend of a friend, but from what I have heard, this man loves meat and cooking and I’ll bet he could get us a steer tail.
If this works out, I’ll post it on one of the recipe threads. It may take awhile.