I'd beg to differ when it comes to rare roasts, but each to their own. There are a few foods that need pre-heating: pastry, souffle, cake for eg, some that benefit from pre-heating, eg roasts other than chicken where the heat seals it. But the weird thing on my oven is that it has a fast heat up option. "Well, I can get hot quickly but only if you tickle my ear and ask me nicely" Under what circumstances would you not want an oven to get to temperature as quickly as possible?