We pre-ordered our food for our November visit and had no issues with it being lost. By the time we walked up to the restaurant and were sitting down at our table waiting for our food, it was all of 30 seconds. A CM just checked us in, verified our order, and we were on our way. The food came out in less than 10 minutes after that. When it works properly like it did for us, it would save you the time in the line to order as well as the coordination/frustration of family members not knowing what they want.
Not sure how payment works though, we did the dining plan and selected that when pre-ordering and they just deducted credits for us.