How bad is it? It's much worse than Highlander II: The Quickening (q.v.)
Should you see it? Only to prove that it's as bad as everyone says.
This is the 5th film in the franchise, depending upon whether one counts re-edited episodes of the television series based on the films and it tries to take something from each of the previous films: the over-the-top acting and fight sequences. It was made for the Sci-Fi network, so it had no budget. The performances look like sleepwalking. The fights look impromptu. The effects look like a high school project. This sounds like it should be so bad that it's funny, but it's just a leaden lump that defies watching.