Just tried 2 of Sonic's relatively new Chili-Cheese Pretzel Dogs, (With Onions).
I think they've been rolling them out on a regional basis over the past several months. Not sure if they're nationwide yet.
Not bad. The rolls were fresh with a good soft pretzel chew. A slightly noticeable amount of pretzel flavor as well. The only thing missing was the pretzel salt on it.
If they could figure out how to get some salt to stick on the bun, it would help it a lot.