Cons: 1) When you highlight the group of files you want to join and it will load them but it will order them differently. (But you can reorder them as needed, or you can add them one at a time in the order you want them in.)
2) WMA files when joined will NOT copy the files at the same bit rate as the original.
3) I merged 4 files together and the merge indicated each file being copied and at the end indicated that all 4 files were joined. HOWEVER, the output file only contained the 1st of the 4 files I selected. A second try resulted in the same result.