There is nothing that my review will add to the 292 other reviews already written for Slyman's, except for me to say that if you are in Cleveland, you have to go. Sure the neighborhood is a little sketchy, sure it isn't as fancy as you may want it to be, but damn the corned beef sandwich is delicious (and one order is big enough for 2 people), and the people who work there are super friendly.
Go now, and let me know how you enjoyed the Ballpark mustard.