I've been looking at my next investment which will be a new lens, probably the 2.8 one. I have some questions that have probably been asked a zillion times but for the life of me can't find what I need to know while doing a search on it... 2.8 and 1.8 are wonderful if your shooting macro and low light.. but how often do you REALLY go that low? Especially if you are shooting a moving subject and not using a tripod? (think: toddlers) With the razor thin depth of field, will this lens be to my advantage? If not, what lens should I go for? Right now, I just shoot with the kit lens. It goes to 3.5 but I never go that far open.