When you ask this kind of question you run a popularity contest with psychological undertones that can be summed up with "the best is the one I have". The owner usually did indeed some cross-comparisons but usually limited, standing in front of a shelf or reading opinions such as here, and over limited time of experience with product use has not considered all relevant questions. Yes, indeed one hand operation is important. The website below is outdated by now but can direct the thinking and the best products out there usually withstood the test of time and those flawed are still flawed:

Steven M. Scharf's World Famous Bicycle Coffee Systems

also

https://people.nscl.msu.edu/~daniel/bicofa.htm