It's worth noting that you shouldn't believe everything you read on the internet. I found somewhere that 145f was medium rare on a steak. The Horror! I way overcooked everyone's steak when we had company and I was trying TRex for the first time. I couldn't bring myself to photograph all that gray, over-done meat. I will say that it was still tender and it had darn good flavor.
Fortunately for me, there was one leftover NY Strip, which my dad and I tried a couple of days later.
On the second attempt I used a fan to stoke up the coals (just a regular floor fan out on the deck pointed up the skirt of my egg) and a new cast iron grate. The results were much more satisfactory.
I might add that we pulled the steak off when it got to 125 or slightly above.
This is how I like it.