I voted for option 2. Watch it if you got time but don't cry yourself to sleep if you don't.
I just saw the series for the first time (on DVD) this past month and although I enjoyed it, I wouldn't place it anywhere near DS9 and B5. Its got some fun characters but story wise I don't think it holds a candle to BS9/B5. As good as some of the characters and relationships are I don't think they live up to the greats of B5/DS9 either: Londo-J'Kar, Odo-Quark, O'Brian-Bashir-Garak.