And I much prefer the ladle method with a 20 pounder or bigger for casting in quantity, particularly with the heavier steel 4-banger molds. Not only am I much faster with a ladle than if I were using my little bottom-pour, but I tire less quickly because I actually lean the mold bottom against the top edge of the pot while I quickly pour. I arguably may be getting better alloy consistency too, since my pot is constantly stirred as I ladle.
The main limit to casting speed isn't the method, but the fact that your mold will get too hot and you'll need to cool it down. You don't want your mold so hot that you have to wait around for the sprue to cool. This problem is easily solved by using two molds, alternating every so many pours. The other limiting factor to speedy production is having to recharge your pot with lead too often. I find 20 pounds to be the minimum size I would consider for my production needs. Also add lead more often in smaller ingots so that you don't ever have to wait for the pot to warm up. I love the small muffin tin size.
Using the above procedure with my DIY ladle, I can EASILY produce about 1,000 bullets per hour with my Lyman 4-bangers.