Dry aged beef can be tricky. I would first refer you to my old thread
here.
The only thing that makes dry aged beef tricky is feeling it for doneness. Depending on the cut and the location of the cut, the meat can be more or less tender than what you might be used to, which is misleading in determining a perfect medium rare. For instance a steak cut from the loin end of a NY strip will be more tender, and a steak cut from the rib end will be less tender.
My suggestion for such a prized (and expensive) piece of meat is to use a digital thermometer. Toss the ego aside and get some help from technology.
If you pan roast a piece of meat like the method in my previous post, it will continue cooking once you pull it from the pan, by about 5 degrees or so. Perfect medium rare is about 129-130F, so pull the meat when the thermometer reaches 124-125. Let it rest for 5 minutes, and make sure to collect the juices that accumulate in the vessel that it's resting in. Slice the meat and pour those juices over the top. The last thing you ever want to do with dry aged beef is serve it with a sauce. I wouldn't even use that aged balsamic I recommend in my previous thread. Just season it with salt and pepper, and serve it with some nice farmer's market tomatoes with a few shavings of parm or crumbles of good blue cheese over the tomatoes (the cheese will pair with the funkiness of the steak beautifully). Alternatively, mushrooms pair very well with dry aged meat because of the earthiness, try to get wild mushrooms if you can and simply sautee them in butter with a sprig of thyme, otherwise stick to portobellos, maitakes, shiitakes, or crimini mushrooms.
Dry aged beef is a real treat, and most people haven't had the real deal. Try to find a 30-day aged cut sometime...it's got a level of funk and cheesiness that is addicting, and goes insanely well with wine, specifically Bordeaux and Barolo.