4-4-2 vs 4-5-1....is it time for a change?

What do my fellow gooners (and others is you wish) think about sticking with a 4-5-1 formation with diaby as a fifth midfielder ...it seems to have worked against Man Utd on Saturday but will this be the case for the rest of our matches? Furthermore, with Ade out for 3 weeks, we will see Bendtner as our lone striker, do you believe this will work? or do you think we should stick to our 4-4-2 formation?