I have used both since...1993 or so. It all depends on what you are doing. Croel is a great design program, we digital print everything out of it. SignLab it an AWSOME vinyl cutting program,
we do all of our viny cutting out of it, even if it was designed in Corel.
Right now we use both Croel X13 and SignLab 9 becaue they both have thier good and bad. PM Me if you have detailed thoughts on what you are looking for.