Steak in Austin?
The Tenderloin George at Gumbos is an amazing experience and it's a lovely location near 8th and Colorado in the Brown Building. There is another very good steak, although at the moment I can't remember what they call it. I don't think you will be disappointed.
The Roaring Fork is also a great local destination.
Austin Land & Cattle (on Lamar around 12th Street) serves a thick, juicy porterhouse steak. Make sure you're hungry because it's huge. Their sides and appetizers are mainly variations on steakhouse standards. The ones I enjoyed most were the baked potatoes with the works and the batter-fried mushrooms. Their salads, desserts, and other main dishes were not successful on my visit. I've attached a link below to that earlier review. AL&C is an independent place with no connection to the chain Texas Land & Cattle.
If you felt like driving out of town to Spicewood, you could try the steak at my favorite steakhouse: Backstage Steakhouse on Hwy 71. I've tasted the porterhouse: It was very flavorful and well prepared. It wasn't, however, as large as the plate, like many people expect it to be. This restaurant is very nice, but not stuffy, with a good wine list and excellent service. The best thing about it, however, is the depth of their menu--their salads, appetizers, desserts, pork dishes, and just about everything I've tasted are very good. I mention the stand-out dishes in that same post, linked to below.
I don't usually order steak when I go out to eat in Austin, but on the few occasions that I have, I liked the peppercorn ribeye steak at Bistro 88 on Bee Caves Road. I prefer their miso-steamed bass, however, so I've only had the steak a couple of times.
If you want a cut of beef that's called steak and don't care if it's grilled directly over a fire, you could try one of the nearby barbecue joints. At Smitty's in Lockhart, for example, the smoked prime rib is delicious. The well-known Cooper's, on Hwy 71 in Llano, does serve sirloin steak that is cooked over direct heat. Of course, the sides are typical of 'cue joints (beans, potato salad) rather than steakhouses. And you may not get a fork with your meat.
Let us know what you discover.