JJ's is not the best cobbler I have ever used, but in the Champaign-Urbana area, they are the best we've got. In short: they are slow and not exactly inexpensive, but they do really good work and can usually save any footwear you have got.
I had a pair of winter boots that I thought were goners. They were cracked and stained, and the zippers on both were separating from the shoe. I took them in, and while it did take them a solid month to repair, I basically got returned a brand new pair of shoes. For new soles, reconstituted zippers, and general refurbishment I paid approximately $25.00 as quoted when I brought them in. It felt expensive, but these boots haven't looked so good in years and I think they added at least another two years onto their walking lives.
The store however, is a jam-packed mess and at first they thought they had lost my shoes altogether because they do not tag or label them aside from repair price. The staff is also not particularly friendly either, but again, they do good work. Also, they are conveniently located across the street from the Amtrak station in downtown Champaign--easy to get to if you do not have a car.
NOTE: this is a cash-only establishment, so come prepared with bills when you pick up your shoes.