The blade type might appear stronger, but if you bang it with your head while cleaning the belly, it will break just as easily. It might not fall off the airplane, but will likely be damaged internally and not able to transmit. This is exactly what happened to me while cleaning the belly of my RV8 - twice. The first one was the little post and ball type. It didn?t break off, but it was bent and when I straightened it out, it would just spin with my fingers, obviously not connected inside. So - I bought the much more expensive (but no better functionally) blade type antenna. I broke this one doing the same thing - cleaning the belly. This one was harder to discover because it looked fine, but when I went to get my IFR transponder cert, it wasn?t working unless I wigggled it - it was slightly loose. I bought another blade antenna, and started jacking up my tail to clean my belly.
BTW - I epoxied the damaged blade antenna back solidly to the mounting base and it appears to be fine now. I?ll sell it to you (cheap) if you?re interested......