EVOO is expensive. I hear people recommend the regular OO.
There's also the pomace, which some claim it accelerates trace. Just tried it for the first time (while being careful), and had no problems. Maybe it depends on what brand is used.
Pomace traces faster and gives a whiter bar. It has more unsaponificables (did I spell that right? Arghhh I'm too tired to care), so in theory more goodies from the oil stay in the soap. I get the cheap-o olive oil at the store that it a mix of pomace and virgin OO for about 3 euros/liter. But I live in a country that produces a lot of olive oil, so I might have more selection than most....
Oh, and yes, extra virgin can be used. I've used it when I've run out of my normal soaping OO, and it's fine, just takes longer to trace. You'll notice on soap calculators that there are separate entries for extra virgin and pomace OO.
