I don't think that anyone has only one prop in their prop collection....I have not tried the 11.5x4 and was not commenting on it....I have tried the 11x5 on my freestyle and love it...I have 12.25x3.75 on my Ext 330 and it does great but it is a lighter and smaller airframe....I would suspect that the 12.25 may be too much prop for this application....I would agree that this all comes into play when selecting a prop....I also think that weather conditions and fuel do make a difference IMO