Easy to get hooked! It's the only way I'll cook steaks anymore. I, personally, don't favor a cast iron sear on a steak (love the BBQ flavor), but I also have a searing burner, so it sears well, quickly. I sear chicken breasts in a little olive oil and butter, in the cast iron (doing that tonight, as a matter of fact), and they are the best! An alternative way to sear on charcoal is to use a charcoal lighter with a grill grate on top...super hot & quick, but more work than the searing burner on the grill.
Sous vide is certainly not the solution to cooking everything, like some insinuate, but it is fantastic on the right things!