Both are promising in their duties and at the same time, both have their disadvantages too.
The manual ignition is a little problematic. Whereas, the automatic runs on battery, therefore, needs proper maintenance.
So, it can be concluded that if you want to avoid extra maintenance, you can skip the option of auto-ignition.
On the other hand, if you want to avoid the use of match sticks or lighter, manual ignition is avoidable.