Everything he said. Plus:
-Autos sometimes turn themselves on for no reason (noise/wind)
-Autos have a tendency to get stuck and either won't turn on or won't turn off until the cutoff is hit, and this is more likely to happen to someone new who is dripping too much or overfilling carts.
When I first looked into these I thought auto was the way to go, but I think hands-down, manual is the absolute best way and you WILL get used to it.