Steak in the OC
I would recommend Mastro's Steakhouse in Costa Mesa. I have been to both Mastro's and Ruth's Chris and I prefer Mastro's by far.
I haven't been to the Mastro's Ocean Club is there a reason you don't have the Mastro's Steakhouse in Costa Mesa amongst your choices? I have heard the Ocean Club has more emphasis on seafood.
You'll find opinions galore on this board, just do a search (see the Search This Board box near the top of the page) for Mastro's, etc.
Personally I'd give it to Mastro's in CM, but I also really like Ruth's Chris. Haven't been to Ocean Club, so I can't say personally. But the "scene" at Ocean Club is supposed to be quite something.
Is Turner New Zealand still in business in Costa Mesa? If so, there is no question... Ruth & Morton are crap. I haven't been to Mastro's but Turner's venison filet cooked Rare with carmelized shallots & bleu cheese is on my all time list... and I have had some serious steaks (Luger's is somewhere on the bottom of my Top 10).
My choice would absolutely be Mastros. Both Ocean Club and Steak House are terrific. I love the courtyard at Ocean Club over any seat at Steakhouse, but Steakhouse has more choices of non-seafood items like prime rib and veal chop.
If I had to pick another place, I would say the best two steaks I have had other than Mastros was at A Restaurant in Newport Beach. I had a stellar Kansas City and Flat Iron there recently.