In my mind, Burrows-Wheeler is a clever trick, but it's not clearly superior to dictionary-based methods. bzip2 beats gzip on compression not because B-W is better, but because it has a larger window size and because of the entropy encoder at the tail end.
7Zip builds on gzip, greatly expanding the window and using an arithmetic encoder at the tail end. It performs better in both time and space over bzip2, making both gzip and bzip2 obsolete
7Zip builds on gzip, greatly expanding the window and using an arithmetic encoder at the tail end. It performs better in both time and space over bzip2, making both gzip and bzip2 obsolete