Is this why you bought 2?I am doing this exact replacement right now. My very preliminary feeling is that the SZ is more forgiving on off-center strikes, especially low on the face. I can’t really compare distances right now because both are missile launchers, and the F9 his a Catalyst 80 in it and the SZ currently has the stock KBS Tour 90, so it’s not a similar build. I should have the SZ built up with a graphite shafts by the end of this week, and then I’ll be able to provide better feedback.