Containment field I have experience with with my red- blue surge though I still need to place it on here. It is only really good if you are able to play more than one spell in a turn. Oh and to answer your question about lands I personally only run 20 lands in any deck that doesn't use landfall. Landfall with me earned 24 lands to be able to at most get 22 triggers at least on a single creature as long as its not
dead. But that is me. I don't like getting mana flooded or mana screwed either. It is truly up to you based on lands. But based on your highest drop that of 6 you would need 25 lands to be consistent.