In my opinion Amir, Danny, and Dennis Murphy came up with very similar on axis Frequency Response graphs. Digging deeper into off axis I think revealed potential for improvement. In the end, set up in your listening room will have the largest impact on listening. I do agree that upgrading to quality crossover components, wire, and terminals provide confidence those items will provide the best signal purity.
Being a DIY guy and inspired by Danny, upgraded my speakers. Made a couple mistakes along the way trying tweaks to the crossover design. Listening and measurement confirmation put me back on the right track. The end result was clearer, cleaner, more dynamic, and better imaging from speakers had been happy with for quite a long time.