Value of Cross-hair AF sensor points

I was shooting at dusk with my A550 and had much better success getting an auto focus lock using the camera's center cross-hair focus sensor point than I did with the other 8 line types. To compensate I would use the center one and half-press and then recompose. This led me to wonder how much extra value more cross-hair focus points have in real life shooting, and how many are enough? So, if you have a camera with more, how much do you use them, appreciate them, want more?

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'Better' is the enemy of 'Good Enough'.