We had a Laptop Lunchbox, a Goodbyn and a few reusbale sandwich/snack bags last year. I bought the Goodbyn when my son complained that he had trouble opening the laptop lunchbox on his own, and didn't like having to raise his hand and ask for help.
I liked having both for a couple reasons:
1. Occasionally, his lunchbox didn't get washed out after school, so it was nice to have something clean to pack in the next morning.
2. Even though I think you * can* pack runny stuff (yogurt, et cetera) in the Goodbyn, my son (he was 5, by the way) had a hard time closing it completely after lunch (he wouldn't get all the compartments sealed), and then he would stick it (vertically) in his backpack. So if I wanted to pack something like that, I would just use the laptop lunchbox--even if he didn't get the lid back on the yogurt completely, it was on, and inside the case, which went inside a thermal lunchbox...so it was pretty sure not to get all over the rest of his backpack.
3. Oh. We also had a stainless steel food canister that we used for hot stuff like soup, pasta, or other leftovers. If I heated them up to a-little-too-hot in the morning, they seemed to be just right by lunch time.
As for school lunches, my son asked a few times about it and I told him he could buy lunch once in a great while--just like we eat fast food once in a while--but that it wasn't going to happen often. He had school lunch three time last year--once when he forgot his lunch (on a day when I was working 45 minutes away--and two other times. He didn't ask for it often (after the first week or two).
We've since moved, and the kids are starting (K and 1) at a local charter school this fall that doesn't serve school lunches. I plan to pick up another Goodbyn (we have two laptop lunch boxes because my husband used to carry one to work) and do more-or-less the same this year.