I have been modeling this and so I am posting the question to see if anyone has comments. When trading a BW Fly....either the M3 or Tony Sizemore's version, do you ever add a call credit spread to the trade. By doing this I can increase the overall profitability of the trade, but with the added risk of more negative vega. If I am more concerned about the trade moving down, then my preference is to use a long put spread to increase vega and lower deltas. The only added risk is more upside risk if the trade rallies. Any thoughts or comments ?