I actually purposely did not want an auto-fill installed specifically for the reason that I wouldn't notice a pool leak until I saw a huge water bill.

I think the "sprinkler fill" works best for me as I can just program in a set number of minutes each week. Also, here in Frisco, TX, we've got water restrictions this Summer in which we're allowed to fill the pool and water the lawn only one day a week (although I'm not sure how they would know if I was filling on an off day! ) The City has been shutting people's sprinkler systems at the curb if they are caught watering their lawns on an off day.