7-zip's GUI is basically an incomplete WinRar clone, and WinRar has a couple more features. Most notably recovery records to be able to recover from mild bit rot, but it can also preserve more NTFS attributes of your files (saving alternate streams, security records, turning hard links into links) and can optionally respect the Archive attribute of files (archiving only files with the attribute set, clearing the attribute after, optionally deleting them).

It's a very solid archival program. I wouldn't recommend that everyone runs out and buys it, and I use 7zip more than Winrar, but it does have some advantages, especially on Windows.