I remember years ago when they were on Liberty and we'd often lunch at that location as students at AIP (when the school was still on Penn). It makes me happy they Yovi's still exists and that the food has stood the test of time. I've been to Chicago on multiple occasions and can say with certainty that they've got it down pat when it comes to authenticity.
I like making my own concoctions. For example I've been known to order a dog with cheese, peppers, pickles, tomato and onion. Add a side of fries and I'm on a hotdog merry-go-round of zing and taste!