While it is very common in France to cook with "crème fraiche" I have never liked it, especially in savoury dishes. White creamy sauces are something that have made me gag my whole life (i.e bechamel, mayonnaise, cream). I really can't do white creamy texture in a savoury dish, especially if warm. As result, as strange as it may sound, I have never had spaghetti alla carbonara because in France, like in many other places, we make it using cream.
Now wait, I have some good news. Last week I read on the Accadamia Italiana Della Cucina that in the original carbonara recipe no cream was used - that suits me very well! So here we go, this is my own version of Spaghetti Alla Carbonara.