Lobster is decadent, I will be the first to admit that. It comes out of its shell in a long, lustrous piece of wonderfulness for dinner. It's dipped in clarified butter (because plain butter is too mundane and not nearly rich enough). Besides, lobster is very, very expensive. If a statement is to be made, it is to be made with lobster.
Why take something so delicate and drench it in cheese sauce? Save your clams! Use crab!
For Valentine's Day, I made several batches of crab mac & cheese for friends and the vote was unanimous-- Sup-licious!