If some of the mirrors are not available to connect due to, for example, network reason, then --connect-timeout=600 will prevent script to give up that mirror, so that lots of times can be wasted.
On the other hand, --connect-timeout=600 with -m0 will give up dead/unavailable mirrors at once.
Besides, --lowest-speed-limit can give up very slow mirrors, which can help to speed up downloading too.
If some of the mirrors are not available to connect due to, for example, network reason, then
--connect-timeout=600will prevent script to give up that mirror, so that lots of times can be wasted.On the other hand,
--connect-timeout=600with-m0will give up dead/unavailable mirrors at once.Besides,
--lowest-speed-limitcan give up very slow mirrors, which can help to speed up downloading too.