The Big Texan of today is not the Big Texan of old. I first encountered it back in 1968. Yes, we fell into the trap seeing the signs for 300 miles about the free steak. BTW, it's 72 ounces, not 48.
Back then it was actually a really good steak house. It was the kind of place where you walked in and it looked like a butcher shop where you got to pick out the exact cut of meat you wanted. The steaks we ordered were excellent.
We didn't try the 72 oz. monster, but someone at a nearby table did. It was absolutely the most disgusting piece of meat I've ever seen. It's basically a 4.5 lb. roast cooked like a steak. It was almost burnt on the outside and raw on the inside.
The next time we tried it was about 10 years later. I understand it had been rebuilt after a fire. The option to pick out your cut of meat was gone. The place had been turned into a real tourist trap and included tableside music with some guy walking around with a fiddle and a woman singing C&W songs. UGGGH.
The steaks weren't bad, but they weren't high quality steakhouse fare either. It was much better though than you'd find at most restaurants at highway interchanges. Much better than Denny's or Craker Barrel and far above Sizzler and Ponderosa, but well below Mortons or G&G.
Unfortunately that was still 27 years ago. I have no idea what it's like now. But if you're on the road and are going to stop for food anyway, you probably can't go wrong. Unless you're familiar with the areas off the interstate a little bit, you'd probably have a hard time finding a better steak on your own.