From your description, you can only be referring to the Rosewood Grille. Here's the lowdown.
The Rosewood Grille was famed for a half-century for its ginormous lobsters and almost equally for the posters advertising them that you'd see all over town, featuring a waiter holding up a giant crustacean almost as big as himself. It was one of those old-school non-casino supper club/gourmet rooms that used to include the likes of Phillip's, Nick's (Henderson), Hill Top House, Cavalier, State Street, and the most recent victim, The Tillerman. Survivors of that era include the Golden Steer, Pamplemouse, and Bob Taylor's Ranch House. But not the Rosewood Grille.
The restaurant you're remembering fondly was indeed originally located across from The Mirage -- in a prime spot now occupied by the Venetian/Palazzo. Back in 2003, after a bitter feud with the owners, who found themselves swamped by their ever-expanding neighbor, Sheldon Adelson paid what was then a record sum for the Strip of $1,565 per square foot for the property on which the restaurant sat. Rosewood Grille then moved south to 3763 Las Vegas Blvd S., in an alley across from the Monte Carlo. This was its home until it finally closed in 2009.
Reviews of the Rosewood Grille were mixed. We've read gushing reports, including one on Yelp.com from a man who loved his lobster so much, he actually named it: "Bart was a gorgeous, bright red 4-lb monstrosity with claws the size of Oprah. I've met bouncers at the Rhino less intimidating."
Max Rubin was a little less complimentary in his assessment in Comp City, where he filed it under "Lobster Traps":
"These are the BIG-lobster places. When you walk in the door, a waiter greets you with a big grin. Why the ear-to-ear? He's about to bankrupt you on your meal! All the menu says (in bold) is market price for the tasty-looking morsels. A closer inspection of the six-point type reveals that they cost anywhere from $18-$22 a pound. And, the smallest they have is a three-pounder.
"The smiling waiter puts timeshare salesmen to shame. He'll power-close your party of four on a 15-pound beauty, and if you don't go for it, he'll make you feel like a tightwad. Tightwad? Gee, that's only $330, plus wine (which isn't cheap), for a steroidal crustacean. And tasty? If you think bulked-out NFL linemen are tough, try nibbling on this mutant that has a bigger tail than your date."
So, Max wasn't such a fan, especially if he was picking up the tab ("Bottom line: If you want lobster, get a good oneāand get it comped.") But for every grouchy old curmudgeon like our dear friend, there are heaps of happy honeymooners, not to mention Kurt S. from Los Angeles, who will never forget that "chunk of seafood the size of a small child" named Bart.
Images appear courtesy of the Neon Museum and of MickVegas on the LVA forums.