I am not an expert on the subject but in college I did have the course using IMHOP the best book ever written on the subject, Antennas by John Kraus, John was also a ham, W8JK and the head of EE at Ohio State. Based on experience and the little I remember from many years ago, the answer to your Question is likely contained in the Question itself.
Why do you want to replace the factory supplied antenna? Because it is a compromise antenna? Of course it is, but so are each of the alternatives you are considering. They just have different sets of compromises built into them by their specific designers.
I know this is going to sound off topic, but bear with me a moment. There is a famous story in Marketing about the initial failures of commercial all-in-one cake mixes to be sold to homemakers. Finally they figure it out, you must leave OUT something and give the homemaker instructions on how to add make the missing ingredient. Then, she feels it is complete by the value added by her addition.
To me, that is the same thing with modern scanners, the owner feels 'better' if he discards the factory supplied (and carefully designed) antenna and selects his OWN back-of-the-set add-on antenna.
The answer is, there is little real difference in performance between ANY back-of-the-set antenna and another. Within limits, they all add up to the same set of design compromises. One is as good (or as poor) as another.
Want to improve your listening? Put up an OUTDOOR aerial