Ardor, the advice given by philso just about summarizes what can be said about the issue of convection against conventional oven. I would like to reiterate the fact that you must experiment with the convection oven so as to get your own feel as to what baking temperature may be suitable for different jobs. This is so because for any oven, when we say "baking temperature" what we really mean is "dial position." Thus if two different ovens are set to the same dial position, they will rarely produce exactly the same temperature. For this reason, experimentation will give you the experience (ie. a number of failed attempts) you need to become at home with any new oven.
The other important point raised by philso is that internal air circulation within a convection oven should not be inhibited by large baking pans or sheets, otherwise hotter areas may be created in the same manner as colder regions are created in an overstuffed refrigerator.
In my case, I have experienced no problem by switching to a professional convection oven. On the contrary, my cookies turned out more evenly baked and my roasts also turned out well. Perhaps a small household convection oven might not perform just the same. As philso mentioned, an oversized or high-speed fan could very well cause some complications during baking.