Charge speed vs battery life

In order to extend the life of the battery, some people say that it is
best to charge it at a slow speed.
Others say that quick charge is fine as long as the battery does not
become too hot.
Yet others claim that quick charge is even _better_, because the charge
time is shorter.

I always thought that a charge current of about 1000 mA is most ideal,
but AccuBattery shows this speed as very low and in red, as if it is bad.

I saw a review of smartphones where a charge time of 1.5 hours was called
'long', whereas I always considered 2.5 hours as normal.

Does anyone know what the most ideal charge speed would be?