I have both and really like them both. I would vote for the CW45 just because I like shooting that caliber. It is a little thicker than the CW9, but conceals easily. I bought the nine first to replace a Kel-Tek and then found the .45 used for a good price. Both have been flawless including break-in period on the CW9. Get the .45 since you already have a 9mm.