The only part of the Sonic reimbursement that is valuable to me is the drink. For health reasons, I don't eat more than a couple of the fries or tots. The tots, when fresh, are excellent, and it takes a lot of willpower to not eat them. I find their burgers to be barely OK at their best, and awful at their worst. I also find that the time goals that Sonic has for their orders make it difficult to deliver a hot and fresh burger. The beef quality is bleh, so when they are not fresh they are about as bad as can be imagined. Usually, when I get a hot and fresh burger, it takes a few minutes more than the time goal. From a consumer standpoint, at any restaurant, I would rather wait a few minutes more for a hot and fresh product. Unfortunately, fast food companies value speed over quality.
A Sonic shop gets me a giant diet soda, two tator tots, and a few bites of lettuce, tomato, and pickle. Therefore, I will only do them when bonused enough that the fee plus a drink is worth the time, effort, and travel.